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CPU-Z OC questions

Last response: in Overclocking
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March 20, 2007 1:47:40 PM

Hi,

I just built a new machine and am interested in overclocking. I'm new to this but I've spent weeks reading up on it.
Machine spec.

Asus P5WDH
E6400
1G Kingston DDR2800
EVGA 7950GT.

My question is related to CPU-Z. Can someone explain these.

Pic1- What is rated FSB and how to is relate to everything else?
Pic2- It says Mem freq is 333. Where did this number come from and isn't it supposed to be 800Mhz?
FSB:D RAM ratio is 4:5. So 266Mhz *5/4= 333Hz. Do I change this?

Pic3- What is this timing table and what do I do with this info?



http://home.comcast.net/~xrunner123/pic1.jpg
http://home.comcast.net/~xrunner123/pic2.jpg
http://home.comcast.net/~xrunner123/pic3.jpg

Thanks

More about : cpu questions

March 20, 2007 3:59:26 PM

Hey there. I'm no expert, but I think I can offer some insight:

Quote:
Pic1- What is rated FSB and how to is relate to everything else?


rated FSB(1068.5) = clock speed (267.1) x 4 ("Quad pumped" bus)
If you set your FSB in the BIOS to 1200, your clock speed will be 300

Quote:
Pic2- It says Mem freq is 333. Where did this number come from and isn't it supposed to be 800Mhz?


It appears you have PC2-5300 RAM, which is DDR2-667, clock speed 333
DDR="Double Data Rate", so DDR number = 2x clock speed
If you had PC2-6400, which is DDR2-800, clock speed would =400

That only takes effect if you unlink the FSB clock and memory clocks.
Otherwise, if linked, your PC2-5300 RAM would be operating at 2 x system clock (267.1) or 534.2 (rounded to 533) which could be handled just as well by PC2-4200 RAM, which runs by default at DDR2-533.

It appears your FSB clock and memory clock are unlinked, allowing the separate speed of 2x333=667. If you want to try a 1:1 ratio, you would look for a number where (number)x4=something the CPU can handle and (number)x2=something the memory can handle.

You could try 333, to "cater" to the memory's rating. You'd get

FSB=333x4 or 1332. This would yeild 333x8(CPU multiplier)=2.66 GHz
(way below what the E6400 can do)
Memory=333x2 or 667, which is what I think your memory is rated for.

There are an awful lot of options of course.

Quote:
Pic3- What is this timing table and what do I do with this info?


I'm not sure. I THINK your Kingston memory is providing factory-sanctioned settings for you to try, in which case it's a reference chart for you to use when making memory speed and timing changes, but someone more experienced than I will have to confirm that.

Hope I've done more good than harm - I'm still new to this too.
March 20, 2007 4:07:45 PM

Thanks for the reply. Well my ram is supposed to be Kingston HyperX 1GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) so this is what is confusing me.
Related resources
March 20, 2007 4:29:27 PM

Does the memory have a label on the stick itself?

Maybe it got mixed up?
March 20, 2007 4:45:23 PM

Quote:
I thought its supposed to say 400 NOT 800 or 333


Yes, it should say 400, unless you change the memory clock speed while unlinked to the FSB clock speed, (which you did) or if you change the FSB speed while the clocks are linked.

So it makes sense that you see 416.
March 20, 2007 5:43:21 PM

FSB is quad pumped - four operations per clock (rising, high, falling, low)
DDR is dual - two operations per clock (rising, falling)

Stock settings should be for FSB 1066/4 = 266 and DDR 800/2 = 400.

If you mess around with clocks they may change. When overclocking it is recommended to change FSB/DRAM ratio for stability. Play around with it. Another thing that at some point you will hit a barrier where your system will become unstable, you can push it higher by raising voltages. This way you can burn your components, so unless you know what you are doing don't mess around with voltages.

And good luck =)
March 20, 2007 6:00:17 PM

Quote:
Pic1- What is rated FSB and how to is relate to everything else?

Your is your effective FSB. Today's CPUs execute 4 operations per clock cycle (which is where you get Quad-Pumped FSB). When calculating clock speeds of a system you want to use your base FSB (266 stock in your case) as a starting point. For example your CPU has a multiplier of 8 (266x8=2.13).

Quote:
Pic2- It says Mem freq is 333. Where did this number come from and isn't it supposed to be 800Mhz?
FSB:D RAM ratio is 4:5. So 266Mhz *5/4= 333Hz. Do I change this?

As you can see the RAM runs at a divider of the base FSB speed and yes it can be changed in the BIOS.

Quote:
Pic3- What is this timing table and what do I do with this info?

The timings table is set by the memory manufacturer and is programed into the SPD chip on the memory module. These are all the memory timings that the memory is rated for. You change change these in the BIOS but this can cause instabilities.
March 21, 2007 12:42:01 PM

Thanks for the replies.
The memory is labeled -
Kingston HyperX 1GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Desktop Memory Model KHX6400D2/1G

Is something wrong? Wouldn't the memory table include the timings for 400Mhz also? And when I boot it says my memory is PC2-5300 not 6400.
March 21, 2007 2:48:42 PM

Your RAM may have been flashed with the wrong SPD. You and call Kingston and report the problem to them, or see if it will run at the rated specs. You will have to set your memory divider manually though. If it runs at 800 with the timings it's rated for I would not worry about it, but if it does not certainly they need to be returned for another pair.

When you start overclocking you will want to make sure the memory speed does not go out of spec. 1:1 ratio would be the best to use while finding your CPU's "sweet spot".
!