Archived from groups: alt.comp.periphs.mainboard.asus (
More info?)
"Paul" <nospam@needed.com> wrote in message
news:nospam-0805052248440001@192.168.1.178...
> In article <Tpyfe.3466$7G.2705@trndny01>, "name" <vze4j6mv@verizon.net>
> wrote:
>
>> "Ben Pope" <benpope81@_REMOVE_gmail.com> wrote in message
>> news:1115599330.8e42cfde29a5007487c7c91c4c1ef477@teranews...
>> > name wrote:
>> >> I post the following for feedback and FYI:
>> >>
>> >> I'm running,
>> >>
>> >> A8N-E
>> >> AMD 64 3200
>> >> 1GB (2x512) Mushkin HP DDR400/PC3200 blue.
>> >>
>> >> I've overclocked with the following settings:
>> >>
>> >> HTT = 250
>> >> HTT multiplier = 4 (at 3 the system won't boot)
>> >> CPU multiplier = 9 (I've read to stay away from half
>> >> multipliers, at 9.5 performance goes way down)
>> >> DRAM frequency = 333 (at 400 system won't boot)
>> >> Memory Timings = at "1T, Auto" or "1T, 2,2,3,5" give similar
>> >> benchmarks.
>> >>
>> >> Benchmarks are as follows:
>> >>
>> >> Aida = memory: read 6317MBs/write 2607MBs
>> >> Sandra = memory : ran int 3985MBs/ram float 4042MBs
>> >>
>> >> Readouts from Win utilities are as follows:
>> >>
>> >> clockgen - CPU = 2500, HTT = 250, Memory = 208.33, PCI-E = 100,
>> >> PCI =
>> >> 33.24
>> >> cpuz - corespeed = 2500, multiplier = 10, HTT = 250, Memory
>> >> =
>> >> 208
>> >>
>> >>
>> >> My questions are does the above seem like a reasonable overclock, or
>> >> am I
>> >> missing something, and can anyone think of anyway to get the DRAM to
>> >> 400?
>> >
>> > Something is a bit strange.
>> >
>> > Look at the speed of your RAM as reported - 208.33MHz.
>> >
>> > Which, when multiplier by the multiplier of 9 has to be 2500MHz, the
>> > speed
>> > of your CPU.
>> >
>> > That has to be about right, looking at the bandwidth from Aida.
>> >
>> > Ben
>> > --
>> > A7N8X FAQ: www.ben.pope.name/a7n8x_faq.html
>> > Questions by email will likely be ignored, please use the newsgroups.
>> > I'm not just a number. To many, I'm known as a String...
>>
>> I'm knew to this, so please explain what seems a bit strange. Is the RAM
>> at
>> 208.33MHz too low, too high?
>>
>> TIA,
>> john
>
> I think 208.33 is the memory clock fed to your DIMMs. With DDR
> (double data rate), there are two transfers per clock cycle.
> What Ben has noticed, is you selected "DDR333" in the BIOS,
> and yet clock gen sees 208.33 * 2 = DDR416! That means in fact
> your RAM is already zipping along. Dual channel DDR400 rates
> would give 6400MB/sec (as a DIMM is 8 bytes wide, two DIMMs
> are 16 bytes wide, 400*16 = 6400MB/sec), and Aida is showing
> 6317. To be more exact, at 208.33, your theoretical memory
> bandwidth is 6666.56MB/sec, and the 6317 value would be
> about 95% efficient.
>
> As for what happened to the memory, remember that when you
> lift the HTT frequency, it scales the memory readings too.
> That means as a user, you will have to turn down the memory
> setting if you happen to lift the HTT any further.
>
> You went from a 200MHz clock for HTT to 250MHz. That is 25%
> faster. Your choice of memory clock 333 * 1.25 = DDR416, and
> lo and behold, that is what the BIOS gave you.
>
> This means, in the usual Asus style (like on my P4C800-E),
> that the memory setting reflects how things would work if
> the FSB was at its normal 200MHz.
>
> For example, assuming a normal FSB clock of 200, and your
> choice of the x10 multiplier, 200*10/12 = 166MHz , and
> with DDR that is DDR333. Asus kept the 12 divider for the
> memory, even though you raised the FSB to 250. 250*10/12=208.33,
> giving DDR416. It just means the BIOS is too stupid to notice
> that the FSB is higher than nominal, which means you'll have
> to turn down the memory a corresponding amount. If you raise
> the FSB by 25%, turn down the memory by 25%, and so on.
>
> HTH,
> Paul
I'm beginning to understand and now, at least, I know what I don't know. I
don't understand how the divider is calcuted. I understand that if you have
DDR400 it means that it's actually running 200 once on the rise and once on
the fall of the clock cycle and that the divider is then1:1. Similarly 333
runs 166 on the rise and fall, but what's the divider? When you say Asus
kept the 12 divider what does the 12 divider actually mean and how is it
calculated. I understand it place in the equation to determine the mem
freq, in your example, 250*10/12=208.33. And that's another thing, where's
the 10 multiplier come from, I'm using a 9 cpu multi? Please help with
this, I'm really trying to understand.
john
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