Memory is rated at different speed but shows much lower speed in CUP-Z

I have two ram sticks.

PCX 1x1GB DDR2 800MHz
Kingston 1x2GB DDR2 800MHz

In the bios, it say that the ram's running at 800MHz. But when I start up CPU-Z, I see the following values for my PCX ram:

http://www.overclockers.com/forums/attachment.php?attachmentid=100555&stc=1&d=1319952056

and the following values for my Kingston ram:

http://www.overclockers.com/forums/attachment.php?attachmentid=100554&stc=1&d=1319951989

If they're set to run at 800MHz, then why is CPU-Z showing 333MHz on my PCX and 400MHz on my kingston? Is something wrong? Or am I just lacking some knowledge?

And what is JEDEC? I tried searching the internet for answers, but everywhere it says that these are standards. I didn't get it.

JDEC is the organization that sets memory standards. One thing you need to know about ram timings is that you are dealing with DDR memory or Double Data Rate. Therefore 400mhz X 2 = ddr2 800mhz. So the one stick is running at the rated speed. You probably need to go into your bios and manualy set both sticks timings. Since its already running them at different speeds I assume that the board is capable of assigning them independently. If not im sure that setting manual speed and timings will fix the issue.
I would use the timings of the one stick at 400 already as my baseline.
So give that a shot and let us know what happens.

ssjwizard said:

JDEC is the organization that sets memory standards. One thing you need to know about ram timings is that you are dealing with DDR memory or Double Data Rate. Therefore 400mhz X 2 = ddr2 800mhz. So the one stick is running at the rated speed. You probably need to go into your bios and manualy set both sticks timings. Since its already running them at different speeds I assume that the board is capable of assigning them independently. If not im sure that setting manual speed and timings will fix the issue.
I would use the timings of the one stick at 400 already as my baseline.
So give that a shot and let us know what happens.

Click to expand...

Thanks for the info mate.
So basically JEDEC #1, 2 and 3 are the 3 standards set by JEDEC for those specific speeds?
And yeah, I'd TOTALLY forgotten that since its DDR, the speed is multiplied by 2.
Btw, what would call this 333MHz speed? Base clock of the memory?

And how will changing the latency timings help? I'm sorry but I'm not that experienced in OC'ing so excuse me if the questions sound silly. I know it WILL help. I just wanna know how.

Also, would you mind giving me the link to any OC'ing tutorial thread that the admins may have posted? I tried searching on my own. Couldn't find any though. I believe they're called stickies?

Btw, if my PCX ram is rated upto 333MHz at JEDEC #3, how is it that I was able to select the speed of 800MHz in the bios? I've had this ram for more than a year now and it's been running on 800MHz the entire time. How was I able to select the option to run it at 800MHz?

The 333/400 mhz is called the memory bus speed, and a few other things. Really it only matters to simply remember that all DDR memory speeds are X2 except for DDR 4/5 which should have been called QDR since they are x4 speeds.

The reason setting speed and timings to manual should help is that its auto detecting the memory wrong. If you set both to manual control it should fix them at whatever speed you tell it. This in effect should correct your situation.


I went over to the Intel CPU forum and found this link in the sticky there. It should help you understand how to overclock your Core2 CPU. Memory overclocking is one of those things that we have to do but no one likes to do so there isnt exactly a full on guide for that. Everyone uses slightly different techniques and I have found a few guides across the web useful in learning to OC memory. Just try doing searches for DDR(/2/3) timings (explained)/(overclocking)/ETC to learn more on the subject.