Whats my FSB speed?

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tjcinnamon

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Mar 10, 2008
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I have a Q6600 OC'd to 3.0GHz stable

I have 4GB of PC2-8500 Dominator

In CPU-Z:

DRAM Frequency is 416.3
FSB😀RAM is 4:5

timings 5-5-5-15

What is the FSB of the machine?

I'm guessing its around 1041, but I am not confident on that at all.

Thanks,
JOe K.
 
Your FSB on the Q6600 is 1066 at stock speeds. Which is a FSB of 266.5 multiplied by the four cores of the Q6600, which comes out to a 1066 FSB.
So at stock your FSB is 266.5 and the Q6600 has a 9x multiplier so 266.5 x 9 = 2398.5 which they round off to 2.4 Ghz....

So at 3.0 Ghz your FSB will be somewhere around 333.3. Since 333.3 x 9 = 2999.7

So just multiply your 3.0Ghz FSB of 333.3 times your 4 cores and you'll see you have a FSB of about 1333Mhz.
 
Uh, here's a tip. Open CPU-Z and look on the CPU tab in the lower left. I marked the location in red for you.

2nhn7d5.jpg
 
Uhhhh, not quite. You got the right answer, but only because you got lucky. The FSB is multiplied by four, not because of the number of cores, but because Intel sends four bits of info per clock cycle. This is true even if you have a dual core, or an older single core P4.

Using only the info provided, SL calculated it correctly. 416.3 divided by the first number (5) multiplied by the second number (4) equals 333. This is the actual speed of the FSB. Because it is quad pumped (not based off of number of cores) the effective speed is 1333MHz.
 
BobfaceBilly is right except you multiply the actual FSB by 4 because intel processors are quad pumped (4 transfers per clock cycle) and not because the processor has 4 cores.

in other words, you always multiply the actual FSB by 4 to get the effective FSB regardless of whether you have a single, dual or quad core CPU.
 
So if my RAM is rated for 1066 FSB does that mean that I am overclocking my RAM?

Is does my RAM have a speed of 1333MHz? Or does this just say that my processor can handle a RAM speed of 1333MHz?
 
you said dram freq is 416.3

multiply that by two and thats what its running at 832.6mhz [your stock is 1066] its ok if your running it under

pc2 8500 can support an fsb of 2132mhz, which your far from, so dont worry, your good
 


Your RAM is constrained by the BSB - the back side bus. Most motherboards use negative pressure to keep the BSB speed close to the FSB - relying on the positive pressure of the FSB to pull it. However this can cause some synchornous slowdown from the drag, which you should compensate for by upping the TBG timing from 4 to 6 and, in some case increasing the voltage by +6.0 gigavolts. This also makes it easier to then overclock the RAM.

If all else fails, some have been known to amplify the compensation by attaching a magnet to the side of the case behind the mobo. If you decide to try this, NOTE THAT THE MAGNET IS INSTALLED OUTSIDE THE CASE, never directly to the back of the mobo which whould just be a crazy thing to do. A bar magnet works best with the poles aligned counter to the Earth's magnetic pole, unless you are in the Southern Hemisphere in which case it should be reversed.
 
As was already said, your RAM runs at the double the front side bus it it is running at a 1:1 ratio. The mobo has a multiplier that will allow you to run the RAM at other than 1:1. So assuming a base FSB clock of 333Mhz, which is probably what you have, 1:1 would be 667Mhz. You have a 4:5 multiplier which gives you a ratio. So a little basic Algebra gives you
4/5 = 333/x -> 5 x 333/4 = 416.25 Ram base clock. The effective speed is 416.25 x 2 = 832.5Mhz. Your RAM is 1066 and you are running 832.5 so your RAM is under clocked by 1066 - 832.5 = 233.5Mhz
 



Would DDR3 multiply 416.3 times three?

Also would I be able to lower my latency times while keeping the same ram speed? Or would it be more advantageous to increase my over RAM speed?
 
416.3 x DDR3 x dual channel x double pumped x 4 sticks x quad core x 5.1 audio = 135,880.08

My apologies to OP if I confused him. However, I can't believe he bought into the 6.0 gigavolts or the magnets - his response afterwards did not appear to be mislead by my comments.
 
No, DDR3 is still DDR (Double Data Rate) so it's still times 2. It can run at higher speeds for reasons I won't go into because it will just confuse you even more. Leave your RAM where it is and let it eat. The changes in RAM speed and timings will have a negligible effect on real world performance gain. Don't fix it if it ain't broke. If you want to play with RAM speeds and timings then you had better do some research before hand.

 
Have you been drinking? :non: I don't remember you as a troller.
 
Word,

I have been doing some reading so far.

Thanks for your help it looks like I have a long way to go.

So far the magnets have had no effect and I have not been able to find them on newegg. I'll have to go check the fridge :)

 
I calculate:

416.3 / X = 5 / 4

Therefore, X = 416.3 * (4 / 5) = 333 MHz raw FSB clock

333 MHz x 4 (quad-pumped) = 1333 MHz FSB


Sincerely yours,
/s/ Paul Andrew Mitchell, Inventor and
Webmaster, Supreme Law Library
http://www.supremelaw.org/

All Rights Reserved without Prejudice
Click to expand...
What this dude said.
 
Rocky. WTF? You forgot to include the [/sarcasm] tag at the end of your post. (btw, how many people know what the BSB actually connects? There used to be one, its not really used any more.)

If you are running your 1066MHz ram at ~832MHz, you can try tightening the timings. If it runs at 1066MHz with 5-5-5-15 timings, you can try to get it down to 4-4-4-12. You might need to go north of 2V to get there however. Its either that, or pat yourself on the back for overspending on your ram, DDR2-800 would have been fine.
 



Agreed, I'm gonna go for the gusto :bounce:
 
I don't know what's up with Rocky. Maybe he is frustrated, we all are, that's why God made alcohol. As far as the RAM, your right money wasted, tightening timings etc. for fun is good, but to no avail.
 
I finally found a BIOS setup that is what I wanted.

Q6600 at 3.00GHz 9x333Mhz at 1.3125v
Corsair PC8500 Dominator at 1:1
the CAS timings are at 4-4-4-15. Would it make a difference at all to have them at 4-4-4-12? Or should I just leave them alone?

Also in having 1:1 ratio with a DRAM frequency of 333MHz I am in effect running my ram at 667MHz right? In order to get my RAM to run at its rated value of 1066MHz would I have to lower my multiplier to 6 and raise my bus speed to 500MHz? Or am I completely off base?

Thanks, JOe K.
 
Yes, it would be running at 667Mhz. Thats why DDR2-800MHz is really the best ram for C2D CPUs. You set the FSB to 400MHz, the FSB:RAM to 1:1, and put the CPU multiplier as high as you (stable) can.

For example, if you have the FSB set to 400MHz, your Ram would be running at 800MHz. You can try a x9 multiplier, but you might need to drop down to 8 to make it stable. (400 x 9 = 3.6GHz, a bit much for a 2.4GHz chip. 400 x 8 = 3.2, possible for more chips.) Every system is different, so you aren't guaranteed to hit this, but its what I'd try for first.
 
The 3.2 worked!

How can I check my RAM voltage in windows? The gigabyte board only allows you to increase the DDR voltage by +.1V, +.2V, +.3V, ect... Therefore, I can't tell what my RAM voltage is at.

Is it located somewhere in CPUz, Coretemp, or FanSpeed?

Thanks,
JOe K.
 
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