CPUZ giving confusing results for Q6600...

[wheely34]

I don't know if this has a simple explaination or not. I downloaded cpuz because i wanted to make sure everything was running at the speeds they were supposed to be running at. The weird thing is, CPUZ is telling me my q6600 is running at 1.6ghz (which is not correct), my multiplier is 6x (which is not correct), my FSB is 1066 (Which is correct), and my memory clock is 400mhz (which is not correct). The first thing that is throwing me off is that this program is telling me my multiplier is 6x. The multiplier is 9x, not 6x. I double checked within the bios and it is set to 9x, although 6x is an option. Since CPUZ is reporting a 6x multiplier, it makes sense that it would also report a frequency of 1600mhz (1066/4=266mhz)(266x6=1600mhz). But, this is not the correct multiplier, therefore, it is not the correct CPU frequency. The multiplier should be 9x resulting in a frequency of 2400mhz, which is what the q6600 is set at (1066/4=266mhz)(266x9=2400mhz) from the factory. Also, my memory, although ddr800, should be running at 533mhz (266x2=532+1=533mhz). CPUZ is reporting that it is running at 400mhz

So basically, I don't understand why this program is reporting a multiplier of 6x, resulting in a frequency of 1600, when it is supposed to be a multiplier of 9x, resulting in a frequency of 2400. Now, from what it looks like, it is saying that the reading is of "Core #0". Does that have something to do with it? Also, to me, it is reporting the wrong memory frequency also. Am I reading this wrong? Below, I posted pictures so everyone can see what I am seeing and maybe can explain this too me. Maybe I am just reading this wrong or missing something...

 

[xc0mmiex]

http://www.tomshardware.com/forum/247006-28-running-full-speed-wrong-multiplier .... this post is a sticky at the top of the CPU section
crank up prime 95 and you should see the numbers jump up

 

[wheely34]

Totally forgot about that speed-step from intel. That makes sense now. I'm going to go d/l that program and see if my multiplier increases to what it's supposed to be at under a load. Thanks for that input, cleared a lot up for me

 

[wheely34]

ok, everything works fine with the multiplier, it was just the speed-step kicking in...but I still don't understand where it's getting its DRAM frequency reading of 400MHz. I thought since I was running PC2-6400 dual channel ram, then it was getting it's reading from this calculation (800/2=400MHz). This is correct, but that's not what my RAM is running at. Since my FSB is running at 266MHz external(1066/4=266MHz), then my ram has to be running at 533MHz (266x2=532+1=533MHz).

So shouldn't it be reading 266MHz, not 400MHz? Or does it not tell you the true speed that the memory is actually running at, just what the rated speed is?

 

[nocteratus]

the fsb/ram ratio is at 2|3 that is why your ram are running @400mhz instead of 533mhz.

In the bios you have set the memory multiplier on auto and it's set at 800Mhz.

 

[xtc28]

At least it is not telling you this!

 

[wheely34]

so what is my ram actually running at? is it running at 533 (266x2+1)? I just dont understand where that 400 is coming from and what it means. Yes, 400 would be correct if I was actually running this RAM at 800mhz (800/2), but I'm not running it at 800.

 

[4745454b]

No, its running at 800MHz. Your using a different multiplier then 1:1.

 

[jsc]

... but I'm not running it at 800.

Yes, you are. Look in the BIOS. Your System Memory Multiplier is set to AUTO so it's using the values programmed into the SPD chip.

Take the value off AUTO and you'll see a table. Select the first 2.0 you see. You should then see the memory clock change to 533 MHz.

 

[MRFS]

> I just dont understand where that 400 is coming from and what it means.


"DDR" means Double Data Rate.

If the DDR DRAM Frequency is 400 MHz,
data is transmitted TWICE per tick of that clock,
or at an effective rate of 800 MHz.

8 bytes are transmitted per effective clock tick
or 8 bytes @ 800 MHz = 6,400 MB/second.

That is why DDR2-800 = PC2=6400.

The "800" means an effective clock rate of 800 MHz (400x2);
the "6400" means a raw bandwidth of 6,400 MB/second (800x8).

CPU-Z reports the raw DRAM Frequency,
NOT the effective clock rate.


MRFS

 

[wheely34]

I think i'm actually confused about determining the speed of the RAM. I thought it all went hand-in-hand. Since my FSB was 1066 quad-pumped, that made it 266 external. My cpu multiplier is 9x, so 266 x 9 = 2.4ghz. I also thought that 266 determined the speed that my ram was currently running at, which i thought was 533 because 266 x 2 = 533 since it's double-pumped ram.

I thought in order to obtain an actual RAM speed of 800MHz, my fsb would have to have been increased to 1600, giving me a 400mhz external bus speed. Take that 400 and multiply it by 2 and you get the 800mhz RAM speed.

I literally just learned all these different calculations just last night because I'd like to OC my q6600, but before I do so, I want to make sure I completely understand it and obviously I am stuck up on the RAM. I just didn't think my ram could actually be running at 800 unless i increased the fsb to 1600. Or at least my system wouldnt be able to utilize the 800MHz speed until i over-clocked.

Maybe I should be asking...am i seeing any performance gains whether i am running the ram at 533, or running it at 800, while running my CPU at the stock 2.4 and the FSB at 1066?

 

[4745454b]

What you wrote is true, but only if you are using a FSB:RAM ratio of 1:1. As nocteratus said, your using 2:3. (I think its actually 3:2) 266 * 3 ~ 800MHz, 800 / 2 = 400. (2:3 would give 177MHz.) Read Jsc's post on how to get it to 1:1.

Maybe I should be asking...am i seeing any performance gains whether i am running the ram at 533, or running it at 800, while running my CPU at the stock 2.4 and the FSB at 1066?

Running it at 800MHz will provide a few extra percentage points. Nothing much. What it will do is lower the highest FSB your ram can run at. Because your running your RAM faster then your FSB, your ram will top out before your FSB will.

 

[wheely34]

ok i understand what's going on now. it was the ratio that was throwing me off. and thats the issue i am running into now...my ram speed is topping out before my CPU. is there a way i can change that ratio to 1:1 (FSB:RAM)??

I have the memory multiplier set to 2.5, which is as low as it can go, and that is giving me 565MHz ram speed if i recall. But this going to keep me from achieving a faster CPU speed because my memory is going to top out faster. anyway to change this? or is that what i'm stuck with?

 

[4745454b]

Have you read the manual? Without having your bios there in front of me, I don't know what values to change. JSC thinks you should have a 2.0 value instead of 2.5. Might want to look for it. Another option, if its there, is to put the memory to DDR2-800. Then as you overclock the bios will automatically change the multiplier to whatever it needs to run the memory at 800MHz.

 

[wheely34]

well stupid me was doing this late last night and did not scroll down the list to see that there is a 2.0. it starts with 2.5, then going to the next incriment up, then the next one up, then it goes back down the 2.0...weird but i have this figured out now. thanks for everyones input in clearing this up for me.

 

[4745454b]

Glad to hear that everything is fine.