fsb speed - why does it matter?

G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

it seems to me that nobody needs a high fsb. since they could just
push the multiplier really high.

I can see the greatness of ddr since the same speed processor can
read/write twice as much per cycle. (i assume that the cpu has to be
ddr to receive or write double)
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

James Hanley wrote:

> it seems to me that nobody needs a high fsb. since they could just
> push the multiplier really high.
>
> I can see the greatness of ddr since the same speed processor can
> read/write twice as much per cycle. (i assume that the cpu has to be
> ddr to receive or write double)

How is it you can see the benefit to 'read/write twice as much per cycle'
yet not see any benefit to more of the cycles?

The CPU communicates to everything through the FSB, and that includes the
memory, so the speed of it directly affects how fast the processor can
communicate. And since the vast majority of that communication is fetching
instructions from memory, it affects how fast it can process them.
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

> it seems to me that nobody needs a high fsb. since they could just
> push the multiplier really high.
>


you cant push the multiplier high because its locked on most modern CPU's

also higher FSB = higher bandwidth = higher performance.

--
From Adam Webb, Overlag
www.tacticalgamer.com
CS:SOURCE server now active :D
"James Hanley" <jameshanley39@yahoo.co.uk> wrote in message
news:930a4bf.0410290627.3ae70dde@posting.google.com...


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.784 / Virus Database: 530 - Release Date: 27/10/2004
 

Glitch

Distinguished
Jul 26, 2004
176
0
18,680
0
Archived from groups: alt.comp.hardware.overclocking (More info?)

"James Hanley" <jameshanley39@yahoo.co.uk> wrote in message
news:930a4bf.0410290627.3ae70dde@posting.google.com...
> it seems to me that nobody needs a high fsb. since they could just
> push the multiplier really high.

LOL and what about the locked multipliers on the majority of processors?
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

"Glitch" <glitch_120@yahoo.com> wrote in message news:<cltte9$bs9$1@bagan.srce.hr>...
> "James Hanley" <jameshanley39@yahoo.co.uk> wrote in message
> news:930a4bf.0410290627.3ae70dde@posting.google.com...
> > it seems to me that nobody needs a high fsb. since they could just
> > push the multiplier really high.
>
> LOL and what about the locked multipliers on the majority of processors?

well, AMD can be unlocked. Maybe intel can. They are not really
'locked' they are 'locked' for people that don't know how to unlock
them.
Just as windows files are 'hidden', it's just a gimmick to make it
'harder'.

> LOL
I fail to see the joke
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o4ng1d1f0ct94@corp.supernews.com>...
> James Hanley wrote:
>
> > it seems to me that nobody needs a high fsb. since they could just
> > push the multiplier really high.
> >
> > I can see the greatness of ddr since the same speed processor can
> > read/write twice as much per cycle. (i assume that the cpu has to be
> > ddr to receive or write double)
>
> How is it you can see the benefit to 'read/write twice as much per cycle'
> yet not see any benefit to more of the cycles?
>
> The CPU communicates to everything through the FSB, and that includes the
> memory, so the speed of it directly affects how fast the processor can
> communicate. And since the vast majority of that communication is fetching
> instructions from memory, it affects how fast it can process them.

The FSB is not THE ONLY THING that affects the speed. The
Multiplier*FSB create the speed. The Processor multiplies the FSB,
and the RAM multiplies the FSB. I am saying that the multiplier can
be increased, so low FSB speed doesn't matter.
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o4ng1d1f0ct94@corp.supernews.com>...
> James Hanley wrote:
>
> > it seems to me that nobody needs a high fsb. since they could just
> > push the multiplier really high.
> >
> > I can see the greatness of ddr since the same speed processor can
> > read/write twice as much per cycle. (i assume that the cpu has to be
> > ddr to receive or write double)
>
> How is it you can see the benefit to 'read/write twice as much per cycle'
> yet not see any benefit to more of the cycles?

Obviously I see the benefit of more cycles. What do you think I meant
when I said "push the multiplier really high". That increases the
cycles per second.
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

"Adam Webb" <adam@ajmysecondname.eclipse.co.uk> wrote in message news:<QqOdnX9R5pNixx_cRVnygQ@eclipse.net.uk>...
> > it seems to me that nobody needs a high fsb. since they could just
> > push the multiplier really high.
> >
>
>
> you cant push the multiplier high because its locked on most modern CPU's

nobody on an overclocking forum should be saying
"oh no, the multiplier is locked, what am I going to do"
Just like no technician is going to say, oh no, the file is 'hidden'
what am I going to do

> also higher FSB = higher bandwidth = higher performance.

yeah, if it's greater width. i'm talking about speed only though.
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

>well, AMD can be unlocked. Maybe intel can. They are not really
>'locked' they are 'locked' for people that don't know how to unlock
>them.
OK Then, Tell us how to unlock the multiplier on the newer locked
CPUs.

>Just as windows files are 'hidden', it's just a gimmick to make it
>'harder'.
Apples and Oranges there.

>
>> LOL
>I fail to see the joke

----------------------------------------------------------------------

You should start drinking prune juice and KY jelly cocktails right now,
that will make things a lot smoother.
-Felatio Love
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

>Obviously I see the benefit of more cycles. What do you think I meant
>when I said "push the multiplier really high". That increases the
>cycles per second.

CPU cycles = yes, memory frequency = no. Only raising the FSB
increases the speed at which the CPU can access the memory.
----------------------------------------------------------------------

You should start drinking prune juice and KY jelly cocktails right now,
that will make things a lot smoother.
-Felatio Love
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

James Hanley wrote:
> David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o4ng1d1f0ct94@corp.supernews.com>...
>
>>James Hanley wrote:
>>
>>
>>>it seems to me that nobody needs a high fsb. since they could just
>>>push the multiplier really high.
>>>
>>>I can see the greatness of ddr since the same speed processor can
>>>read/write twice as much per cycle. (i assume that the cpu has to be
>>>ddr to receive or write double)
>>
>>How is it you can see the benefit to 'read/write twice as much per cycle'
>>yet not see any benefit to more of the cycles?
>>
>>The CPU communicates to everything through the FSB, and that includes the
>>memory, so the speed of it directly affects how fast the processor can
>>communicate. And since the vast majority of that communication is fetching
>>instructions from memory, it affects how fast it can process them.
>
>
> The FSB is not THE ONLY THING that affects the speed. The
> Multiplier*FSB create the speed. The Processor multiplies the FSB,

I didn't say a thing about the CPU speed. I was talking about the FSB: the
'point' of the discussion. And, as I said, the only means the CPU has to
COMMUNICATE to anything, including the memory, is through the FSB.

Just how fast do you think it can get instructions to execute if you turned
the FSB down to 1 Hz, eh?

It doesn't make any difference how fast the CPU can execute instructions if
you can't feed it the instructions to execute.

> and the RAM multiplies the FSB.

No. It doesn't 'multiply' the FSB. It operates at the memory bus clock rate.

> I am saying that the multiplier can
> be increased, so low FSB speed doesn't matter.

You missed the entire point, and are incorrect.
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

James Hanley wrote:

> David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o4ng1d1f0ct94@corp.supernews.com>...
>
>>James Hanley wrote:
>>
>>
>>>it seems to me that nobody needs a high fsb. since they could just
>>>push the multiplier really high.
>>>
>>>I can see the greatness of ddr since the same speed processor can
>>>read/write twice as much per cycle. (i assume that the cpu has to be
>>>ddr to receive or write double)
>>
>>How is it you can see the benefit to 'read/write twice as much per cycle'
>>yet not see any benefit to more of the cycles?
>
>
> Obviously I see the benefit of more cycles. What do you think I meant
> when I said "push the multiplier really high". That increases the
> cycles per second.

No, increasing the multiplier does NOT increase the FSB cycles.
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

GTD <duh@stoopid.net> wrote in message news:<p7g8o0tc1hmgsf01s8gtentv5igpg8otml@4ax.com>...
> >Obviously I see the benefit of more cycles. What do you think I meant
> >when I said "push the multiplier really high". That increases the
> >cycles per second.
>
> CPU cycles = yes, memory frequency = no. Only raising the FSB
> increases the speed at which the CPU can access the memory.
> ----------------------------------------------------------------------

memory frequency can be increased to a multiple of the FSB even before
DDR is 'applied'. I have an option in my BIOS to set my DDR-SDRAM
frequency, I can set my FSB to 100 and my SDRAM to 266 (effective).
So my actual RAM speed is operating at a frequency of 133 internally,
which is FSB*(5/4). I don't know if it uses its own multiplier to do
that, I think it probably does.
So both RAM and CPU can operate at a frequency that is a multiple of
the FSB.
So memory frequency can be increased without increasing the FSB.

However, against me, I will say that it just occurred to me that the
speed at which the CPU and RAM interfaces with the FSB is still going
to be the speed of the FSB, regardless of how high their internals
speeds are. Thus if one were to weigh doubling the FSB against
doubling the Multiplier(timesing the current value of the multiplier
by 2), they would find that doubling the FSB makes for a faster
computer, since it would have doubled not just both the internal
frequency of the CPU and RAM - thus their bandwidth, but the speed
and thus bandwidth of the bus.

(i'm assuming bandwidth=throughput, but I cannot check at this moment,
since I'm leaving in a minute, so I have to click Send now!!

Thanks for your response.
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

On 31 Oct 2004 04:21:20 -0800, jameshanley39@yahoo.co.uk (James
Hanley) wrote:

>GTD <duh@stoopid.net> wrote in message news:<p7g8o0tc1hmgsf01s8gtentv5igpg8otml@4ax.com>...
>> >Obviously I see the benefit of more cycles. What do you think I meant
>> >when I said "push the multiplier really high". That increases the
>> >cycles per second.
>>
>> CPU cycles = yes, memory frequency = no. Only raising the FSB
>> increases the speed at which the CPU can access the memory.
>> ----------------------------------------------------------------------
>
>memory frequency can be increased to a multiple of the FSB even before
>DDR is 'applied'. I have an option in my BIOS to set my DDR-SDRAM
>frequency, I can set my FSB to 100 and my SDRAM to 266 (effective).
>So my actual RAM speed is operating at a frequency of 133 internally,
>which is FSB*(5/4). I don't know if it uses its own multiplier to do
>that, I think it probably does.
>So both RAM and CPU can operate at a frequency that is a multiple of
>the FSB.
>So memory frequency can be increased without increasing the FSB.
Yes, that is correct

>
>However, against me, I will say that it just occurred to me that the
>speed at which the CPU and RAM interfaces with the FSB is still going
>to be the speed of the FSB, regardless of how high their internals
>speeds are.
Yes, that is what I was trying to articulate. I forgot about the
presence of FSB/Memory Dividers

> Thus if one were to weigh doubling the FSB against
>doubling the Multiplier(timesing the current value of the multiplier
>by 2), they would find that doubling the FSB makes for a faster
>computer, since it would have doubled not just both the internal
>frequency of the CPU and RAM - thus their bandwidth, but the speed
>and thus bandwidth of the bus.
>
>(i'm assuming bandwidth=throughput, but I cannot check at this moment,
>since I'm leaving in a minute, so I have to click Send now!!
>
>Thanks for your response.

----------------------------------------------------------------------

You should start drinking prune juice and KY jelly cocktails right now,
that will make things a lot smoother.
-Felatio Love
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

James Hanley wrote:
> "Adam Webb" <adam@ajmysecondname.eclipse.co.uk> wrote in message
> news:<QqOdnX9R5pNixx_cRVnygQ@eclipse.net.uk>...
>>> it seems to me that nobody needs a high fsb. since they could just
>>> push the multiplier really high.
>>
>> you cant push the multiplier high because its locked on most modern
>> CPU's
>
> nobody on an overclocking forum should be saying
> "oh no, the multiplier is locked, what am I going to do"
> Just like no technician is going to say, oh no, the file is 'hidden'
> what am I going to do.

Better analogy: the technician saying "oh no, someone has wiped the disk
then turned it into slag in a blast furnace, what am I going to do?". Given
that people have spent close to 6 years trying to unlock Intel CPUs (no
success) and about 1 year trying to unlock locked AMD chips (no success), I
doubt there's going to be much progress on either front. The general view is
that both companies are using fuses inside the die, which can't be altered
once set.

>> also higher FSB = higher bandwidth = higher performance.
>
> yeah, if it's greater width. i'm talking about speed only though.

Umm, say what? It's obvious that more throughput = more performance, and
throughput = bus width * bus speed, so increasing the bus speed (FSB)
obviously increases performance. Or do you think a Athlon running sync with
PC66 RAM (66MHz FSB, SDR, 64 bits wide) would perform just as well as the
identical CPU running sync with PC3200 RAM (200MHz FSB, DDR, 64 bits wide)?

--
Michael Brown
www.emboss.co.nz : OOS/RSI software and more :)
Add michael@ to emboss.co.nz - My inbox is always open
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

"Michael Brown" <see@signature.below> wrote in message news:<SOUgd.1267$op3.55721@news.xtra.co.nz>...
> James Hanley wrote:
> > "Adam Webb" <adam@ajmysecondname.eclipse.co.uk> wrote in message
> > news:<QqOdnX9R5pNixx_cRVnygQ@eclipse.net.uk>...
> >>> it seems to me that nobody needs a high fsb. since they could just
> >>> push the multiplier really high.
> >>
> >> you cant push the multiplier high because its locked on most modern
> >> CPU's
> >
> > nobody on an overclocking forum should be saying
> > "oh no, the multiplier is locked, what am I going to do"
> > Just like no technician is going to say, oh no, the file is 'hidden'
> > what am I going to do.
>
> Better analogy: the technician saying "oh no, someone has wiped the disk
> then turned it into slag in a blast furnace, what am I going to do?". Given
> that people have spent close to 6 years trying to unlock Intel CPUs (no
> success) and about 1 year trying to unlock locked AMD chips (no success),

6 years? - but there are loads of articles on unlocking AMD chips, i'm
sure I think I saw one for the AMD XP 1500+, that's less than 6 years
old isn't it?

>The general view is
> that both companies are using fuses inside the die, which can't be altered
> once set.

bastards.
So how can anybody overclock? Just by upping the FSB to whatever the
mobo supports?
I suppose that a CPU will have a built in multiplier at a fixed value,
and will assume a certain FSB speed. So if the FSB is lower then it's
underclocked. If it's higher then it's overclocked. Or does it not
even derive its clock by multiplying the FSB clock?
Would most people have the FSB at the highest setting suported anyway,
and they'd have a CPU that supports it, so how would they overclock?
(they cna't up the FSB clock because it's already on the highest, and
they can't up the multiplier because it's properly locked)

> >> also higher FSB = higher bandwidth = higher performance.
> >
> > yeah, if it's greater width. i'm talking about speed only though.
>
> Umm, say what? It's obvious that more throughput = more performance, and
> throughput = bus width * bus speed, so increasing the bus speed (FSB)
> obviously increases performance. Or do you think a Athlon running sync with
> PC66 RAM (66MHz FSB, SDR, 64 bits wide) would perform just as well as the
> identical CPU running sync with PC3200 RAM (200MHz FSB, DDR, 64 bits wide)?

oh yeah, I just realised that in a post in reply to that other Geezer
in the thread.
btw, Some software tells me that my RAM is operating at a multiple of
the processor speed. I can put my FSB=100 and have 266MHZ
DDR-SDRAM(actual speed 133MHz) So si sandra tells me it's a multiple
of my FSB.
Is it correct that RAM uses a multiplier too? It sure looks like it
from si sandra, though there is no option in the BIOS to set it, I can
only set the ram frequency. I thought that RAM derives its speed from
the FSB, the FSB is like the base clock, so it must multiply it,
strange that there's no option in the bios to set the ram multiplier.
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o8u0kk4kphbbd@corp.supernews.com>...
> James Hanley wrote:
>
> > David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o4ng1d1f0ct94@corp.supernews.com>...
> >
> >>James Hanley wrote:
> >>
> >>
> >>>it seems to me that nobody needs a high fsb. since they could just
> >>>push the multiplier really high.
> >>>
> >>>I can see the greatness of ddr since the same speed processor can
> >>>read/write twice as much per cycle. (i assume that the cpu has to be
> >>>ddr to receive or write double)
> >>
> >>How is it you can see the benefit to 'read/write twice as much per cycle'
> >>yet not see any benefit to more of the cycles?
> >
> >
> > Obviously I see the benefit of more cycles. What do you think I meant
> > when I said "push the multiplier really high". That increases the
> > cycles per second.
>
> No, increasing the multiplier does NOT increase the FSB cycles.

I knew that, it increases cycles per second, but just CPU cycles.
So yeah. I just realised that:
Increasing the multiplier increases CPU cycles (not FSB cycles of
course).
Increasing the FSB increases both - that is what hadn't occurred to me
:p

So if the system supported it(processor was unlocked and very
underclocked) doubling the FSB is better than doubling the current
value of the multiplier. It's better to have a faster FSB(thus
increasing CPU cycles and FSB cycles) than to have a slower FSB and a
larger multiplier, which would only increase CPU cycles.

More CPU cycles --> more CPU bandwidth
More FSB cycles --> more FSB bandwidth

I suppose bandwidth and throughput are the same thing



thanks for your response
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o8ttn1rsqsm79@corp.supernews.com>...
> James Hanley wrote:
> > David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o4ng1d1f0ct94@corp.supernews.com>...
> >
> >>James Hanley wrote:
> >>
> >>
<snip>

> Just how fast do you think it can get instructions to execute if you turned
> the FSB down to 1 Hz, eh?
> It doesn't make any difference how fast the CPU can execute instructions if
> you can't feed it the instructions to execute.

I was wrong on that one. thanks for your response

> > and the RAM multiplies the FSB.
>
> No. It doesn't 'multiply' the FSB. It operates at the memory bus clock rate.

Ok. The thing that made me think it multiplied the FSB was
a)If my memory serves me correctly, Si Sandra lists alongside the
actual and effective memory clock speeds, a multiple, which seems to
work out the actual memory speed correctly if taken as a multiple of
the actual fsb speed.
b)the FSB is often called the base clock, since - i've been told - all
clocks in the system are derived from it - thus, I thought maybe the
memory clock speed was derived from it too (with a multiplier).

I can accept that si sandra is being misleading and that the clock is
independent, since the BIOS does not have a setting to change any
'memory multiplier'.

Maybe the thing I had been told that "all clocks in the system are
derived from the base clock - fsb clock" is wrong, and should read
"all clocks in the system are synchronized with the base/fsb clock"


So the FSB has its own clock, the Synchronous Memory has its own
clock.
But the PCI, AGP and CPU have a derived clock? (I make this
statement by looking at where in the bios i can set the multiplier)

thanks
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

try unlocking an A64 or a P3/P4

XP's yeah sure you can unlock them, but why? the higher the fsb the better

--
From Adam Webb, Overlag
www.tacticalgamer.com
CS:SOURCE server now active :D
"James Hanley" <jameshanley39@yahoo.co.uk> wrote in message
news:930a4bf.0410310817.50f2267e@posting.google.com...
> "Michael Brown" <see@signature.below> wrote in message
news:<SOUgd.1267$op3.55721@news.xtra.co.nz>...
> > James Hanley wrote:
> > > "Adam Webb" <adam@ajmysecondname.eclipse.co.uk> wrote in message
> > > news:<QqOdnX9R5pNixx_cRVnygQ@eclipse.net.uk>...
> > >>> it seems to me that nobody needs a high fsb. since they could just
> > >>> push the multiplier really high.
> > >>
> > >> you cant push the multiplier high because its locked on most modern
> > >> CPU's
> > >
> > > nobody on an overclocking forum should be saying
> > > "oh no, the multiplier is locked, what am I going to do"
> > > Just like no technician is going to say, oh no, the file is 'hidden'
> > > what am I going to do.
> >
> > Better analogy: the technician saying "oh no, someone has wiped the disk
> > then turned it into slag in a blast furnace, what am I going to do?".
Given
> > that people have spent close to 6 years trying to unlock Intel CPUs (no
> > success) and about 1 year trying to unlock locked AMD chips (no
success),
>
> 6 years? - but there are loads of articles on unlocking AMD chips, i'm
> sure I think I saw one for the AMD XP 1500+, that's less than 6 years
> old isn't it?
>
> >The general view is
> > that both companies are using fuses inside the die, which can't be
altered
> > once set.
>
> bastards.
> So how can anybody overclock? Just by upping the FSB to whatever the
> mobo supports?
> I suppose that a CPU will have a built in multiplier at a fixed value,
> and will assume a certain FSB speed. So if the FSB is lower then it's
> underclocked. If it's higher then it's overclocked. Or does it not
> even derive its clock by multiplying the FSB clock?
> Would most people have the FSB at the highest setting suported anyway,
> and they'd have a CPU that supports it, so how would they overclock?
> (they cna't up the FSB clock because it's already on the highest, and
> they can't up the multiplier because it's properly locked)
>
> > >> also higher FSB = higher bandwidth = higher performance.
> > >
> > > yeah, if it's greater width. i'm talking about speed only though.
> >
> > Umm, say what? It's obvious that more throughput = more performance, and
> > throughput = bus width * bus speed, so increasing the bus speed (FSB)
> > obviously increases performance. Or do you think a Athlon running sync
with
> > PC66 RAM (66MHz FSB, SDR, 64 bits wide) would perform just as well as
the
> > identical CPU running sync with PC3200 RAM (200MHz FSB, DDR, 64 bits
wide)?
>
> oh yeah, I just realised that in a post in reply to that other Geezer
> in the thread.
> btw, Some software tells me that my RAM is operating at a multiple of
> the processor speed. I can put my FSB=100 and have 266MHZ
> DDR-SDRAM(actual speed 133MHz) So si sandra tells me it's a multiple
> of my FSB.
> Is it correct that RAM uses a multiplier too? It sure looks like it
> from si sandra, though there is no option in the BIOS to set it, I can
> only set the ram frequency. I thought that RAM derives its speed from
> the FSB, the FSB is like the base clock, so it must multiply it,
> strange that there's no option in the bios to set the ram multiplier.


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.786 / Virus Database: 532 - Release Date: 29/10/2004
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

> Obviously I see the benefit of more cycles. What do you think I meant
> when I said "push the multiplier really high". That increases the
> cycles per second.

theres no point having a 2000mhz CPU if its connection to the rest of the
system is only 100mhz.

if the ram is running at 200mhz, and the fsb is running at 100mhz do you
really think it gets max performance out of the ram? no it just sits there
waiting for stuff to do, exaclty what the CPU does also, sure it can do
stuff at 2000mhz but it has to send it down a small 100mhz pipe, dont you
think thats a rather SLOW way of doing things?

the fsb is the limit on todays systems hence the reason for pushing it so
high, id much rather have a 8x250 than a 10x200 A64 system.


Oh and about the locks:

Intel P3 and P4s can not be unlocked (ES dont count)
A64s cant go up on multiplyers, just down.
FX's are totaly unlocked.
2003 week >39 XP's are unlockable, but alittle harder than before
2003 week <39 XP's are unlockable with ease.


--
From Adam Webb, Overlag
www.tacticalgamer.com
CS:SOURCE server now active :D


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.786 / Virus Database: 532 - Release Date: 29/10/2004
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

James Hanley wrote:
> David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o8u0kk4kphbbd@corp.supernews.com>...
>
>>James Hanley wrote:
>>
>>
>>>David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o4ng1d1f0ct94@corp.supernews.com>...
>>>
>>>
>>>>James Hanley wrote:
>>>>
>>>>
>>>>
>>>>>it seems to me that nobody needs a high fsb. since they could just
>>>>>push the multiplier really high.
>>>>>
>>>>>I can see the greatness of ddr since the same speed processor can
>>>>>read/write twice as much per cycle. (i assume that the cpu has to be
>>>>>ddr to receive or write double)
>>>>
>>>>How is it you can see the benefit to 'read/write twice as much per cycle'
>>>>yet not see any benefit to more of the cycles?
>>>
>>>
>>>Obviously I see the benefit of more cycles. What do you think I meant
>>>when I said "push the multiplier really high". That increases the
>>>cycles per second.
>>
>>No, increasing the multiplier does NOT increase the FSB cycles.
>
>
> I knew that, it increases cycles per second, but just CPU cycles.
> So yeah. I just realised that:
> Increasing the multiplier increases CPU cycles (not FSB cycles of
> course).
> Increasing the FSB increases both - that is what hadn't occurred to me
> :p

It isn't because of increasing 'both': that's a matter of the CPU
multiplier being locked, or not.

A 1.83 Ghz processor on a 333 Mhz FSB will perform better than a 1.83 Ghz
processor running on a 266 Mhz FSB, whether you accomplish the test by
buying two different processors or using one with an adjustable multiplier.

It isn't as dramatic an improvement as changing the CPU speed (multiplier)
partly because it's offset by the L2 cache.


> So if the system supported it(processor was unlocked and very
> underclocked) doubling the FSB is better than doubling the current
> value of the multiplier.

It depends on what you mean by that.

If you mean taking a processor of speed X on FSB Y and *either* doubling
the FSB *or* doubling the CPU speed then no, doubling the FSB, alone, is
not as good as doubling the CPU speed, alone.

If you mean, as I suspect you do, doing one or the other to end up with the
same CPU speed after it's all said and done, then yes, because a processor
at speed X will perform better if it also has a faster FSB (within reason).

Let's put it to a practical example. I have an unlocked mobile Barton 2400
on a DFI motherboard that let's me adjust everything, so I can run it
overclocked to 2.2 Ghz at 266 Mhz FSB, 333 Mhz FSB, or 400 Mhz FSB (if I
stay at 'standard' FSBs) by adjusting the multiplier accordingly. Which do
you think will give me the best performance?

> It's better to have a faster FSB(thus
> increasing CPU cycles and FSB cycles) than to have a slower FSB and a
> larger multiplier, which would only increase CPU cycles.

You're mixing apples and oranges. In one case you alter the CPU speed but
not in the other. That might be a constraint imposed when using a locked
multiplier CPU but it confuses the matter that increasing the FSB, alone,
improves processor performance because more instructions can get to it per
second.

>
> More CPU cycles --> more CPU bandwidth

No. More 'CPU cycles' (all else being equal) ---> more instructions
executed per second, assuming it can GET the instructions at that rate.

> More FSB cycles --> more FSB bandwidth
>
> I suppose bandwidth and throughput are the same thing

Bandwidth is capability and throughput is what is actually going through.

>
> thanks for your response
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

James Hanley wrote:

> David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o8ttn1rsqsm79@corp.supernews.com>...
>
>>James Hanley wrote:
>>
>>>David Maynard <dNOTmayn@ev1.net> wrote in message news:<10o4ng1d1f0ct94@corp.supernews.com>...
>>>
>>>
>>>>James Hanley wrote:
>>>>
>>>>
>
> <snip>
>
>>Just how fast do you think it can get instructions to execute if you turned
>>the FSB down to 1 Hz, eh?
>>It doesn't make any difference how fast the CPU can execute instructions if
>>you can't feed it the instructions to execute.
>
>
> I was wrong on that one. thanks for your response
>
>
>>>and the RAM multiplies the FSB.
>>
>>No. It doesn't 'multiply' the FSB. It operates at the memory bus clock rate.
>
>
> Ok. The thing that made me think it multiplied the FSB was
> a)If my memory serves me correctly, Si Sandra lists alongside the
> actual and effective memory clock speeds, a multiple, which seems to
> work out the actual memory speed correctly if taken as a multiple of
> the actual fsb speed.
> b)the FSB is often called the base clock, since - i've been told - all
> clocks in the system are derived from it - thus, I thought maybe the
> memory clock speed was derived from it too (with a multiplier).

Well, more like 'system clock' but it, itself, is 'multiplied' from a lower
clock.

The point I was making is that there is no 'multiplier' *in* memory sticks,
as there is with the processor. Memory simply runs at the speed of the bus
it's on.

Typically the memory bus operated at the same speed as the FSB but modern
northbridge implementations often allow for running it at some 'ratio' to
the FSB. That 'not the same as FSB' memory bus clock is generated by the
northbridge and it's not a 'memory' clock, as in the sense of the CPU, it's
a memory *bus* clock.

"Multiplier" has multiple (pun) meanings. One refers to a mathematical
relationship. I.E. 266 is 2 times 133. The other refers to how that number
is physically implemented in the hardware.

While DDR is 'x2' SDR, in terms of theoretical bandwidth, it is not done by
'multiplying' a 133 Mhz clock to get a 266 Mhz clock. It is accomplished by
sending data on both the leading and trailing edges of the same, as SDR, clock.

I.E. | 1 cycle |
____ ____
| | | |
clock --- ---- ---

| | | |
SDR Data | Data |
| | | |
DDR Data Data Data Data

The clock speed is the same and there is no 'multiplier' creating a new,
'double speed' clock. Yet the effective speed is '2x' because it sends the
data twice per clock.

The CPU *does* have a 'multiplier'.

I.E. __________________Processor Package_______________
| |
System | |
clock --> CPU pin --> phase lock loop --> internal CPU clock |
| ^ |
| | |
| multiplier |
|__________________________________________________|

The internal CPU clock operates at xMultiplier the external clock.


> I can accept that si sandra is being misleading and that the clock is
> independent, since the BIOS does not have a setting to change any
> 'memory multiplier'.

I'm not sure what 'significance' you're trying to ascribe to 'derived' vs
'independent'.


> Maybe the thing I had been told that "all clocks in the system are
> derived from the base clock - fsb clock" is wrong, and should read
> "all clocks in the system are synchronized with the base/fsb clock"

It's an oversimplification that ignores what part of the system is doing
what and why.

> So the FSB has its own clock, the Synchronous Memory has its own
> clock.

It's both 'their own clock' and derived.

> But the PCI, AGP and CPU have a derived clock? (I make this
> statement by looking at where in the bios i can set the multiplier)


>
> thanks
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

James Hanley wrote:

> "Michael Brown" <see@signature.below> wrote in message news:<SOUgd.1267$op3.55721@news.xtra.co.nz>...
>
>>James Hanley wrote:
>>
>>>"Adam Webb" <adam@ajmysecondname.eclipse.co.uk> wrote in message
>>>news:<QqOdnX9R5pNixx_cRVnygQ@eclipse.net.uk>...
>>>
>>>>>it seems to me that nobody needs a high fsb. since they could just
>>>>>push the multiplier really high.
>>>>
>>>>you cant push the multiplier high because its locked on most modern
>>>>CPU's
>>>
>>>nobody on an overclocking forum should be saying
>>>"oh no, the multiplier is locked, what am I going to do"
>>>Just like no technician is going to say, oh no, the file is 'hidden'
>>>what am I going to do.
>>
>>Better analogy: the technician saying "oh no, someone has wiped the disk
>>then turned it into slag in a blast furnace, what am I going to do?". Given
>>that people have spent close to 6 years trying to unlock Intel CPUs (no
>>success) and about 1 year trying to unlock locked AMD chips (no success),
>
>
> 6 years? - but there are loads of articles on unlocking AMD chips, i'm
> sure I think I saw one for the AMD XP 1500+, that's less than 6 years
> old isn't it?

You didn't pay attention to what he wrote. The 6 years was with regard to
Intel processors and he said "about 1 year" with respect to AMD processors.

>
>
>>The general view is
>>that both companies are using fuses inside the die, which can't be altered
>>once set.
>
>
> bastards.

It all started when unscrupulous resellers simply remarked lower speed
chips to higher speed ones so they could profit by selling cheap processors
at the higher price.

> So how can anybody overclock? Just by upping the FSB to whatever the
> mobo supports?

Correct. Except that Intel has now tried to lock the FSB.

> I suppose that a CPU will have a built in multiplier at a fixed value,
> and will assume a certain FSB speed. So if the FSB is lower then it's
> underclocked. If it's higher then it's overclocked.

Correct

> Or does it not
> even derive its clock by multiplying the FSB clock?

It has no other choice.

> Would most people have the FSB at the highest setting suported anyway,
> and they'd have a CPU that supports it, so how would they overclock?
> (they cna't up the FSB clock because it's already on the highest, and
> they can't up the multiplier because it's properly locked)

That's why overclockerr's PICK the best processor to overclock, and a
motherboard that provides the ability to do so.


<snip>
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

Adam Webb wrote:
[...]
> Oh and about the locks:
>
> Intel P3 and P4s can not be unlocked (ES dont count)
> A64s cant go up on multiplyers, just down.
> FX's are totaly unlocked.
> 2003 week >39 XP's are unlockable, but alittle harder than before

2003 week >39 XP's are not unlockable. Show me a post week 39 desktop CPU
running at anything but the default multiplier on a NF2. Or the cache being
enabled on a post week 39 Duron. You can get around the L3 lock on some
chipsets by enabling PowerNow, but you certainly can't unlock the chip.

> 2003 week <39 XP's are unlockable with ease.

2003 week <39 XP's aren't locked :) Well, I suppose the Palomino is if you
want to go back that far (and is easily unlockable as you noted).

--
Michael Brown
www.emboss.co.nz : OOS/RSI software and more :)
Add michael@ to emboss.co.nz - My inbox is always open
 
G

Guest

Guest
Archived from groups: alt.comp.hardware.overclocking (More info?)

> > 2003 week >39 XP's are unlockable, but alittle harder than before
>
> 2003 week >39 XP's are not unlockable. Show me a post week 39 desktop CPU
> running at anything but the default multiplier on a NF2. Or the cache
being
> enabled on a post week 39 Duron. You can get around the L3 lock on some
> chipsets by enabling PowerNow, but you certainly can't unlock the chip.

oooooh they not unlockable at all? i thought there was a hardway to do it? i
dunno my last XP was a week 20 something ;-)

--
From Adam Webb, Overlag
www.tacticalgamer.com
CS:SOURCE server now active :D


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.786 / Virus Database: 532 - Release Date: 30/10/2004
 

Similar threads


ASK THE COMMUNITY