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ocuser001
10-30-09, 07:52 PM
I have two DIMMs from different companies. Both are rated DDR2 800, however, my BIOS shows that it is 667MHz Unganged. Why is this so?

I inserted one stick at a time, and each time the BIOS showed it was 800MHz Unganged, but when I put them together it shows up as 667MHz.

One is a Crucial and another PNY

1.http://www.crucial.com/store/partspe...e=CT25664AA800
2. http://www.amazon.com/PNY-MD2048SD2-.../dp/B001GF1M1E

The CUP-Z software also shows that both are rated 800MHz, but the DRAM frequency is at 334.8MHz. What is going on here? Attached are some screenshots
EarthDog
10-30-09, 07:55 PM
Corsair link doesnt work, but your CPUz shots show the timings are NOT the same on the sticks. You will need to manually set your timings to the slower stick (the one with 6-6-6-18-24 timings) and set the muliplier to reach 400Mhz (DDR 800) speeds.
ocuser001
10-30-09, 08:06 PM
Thanks for the reply. I have never overclocked. What are the downsides (stability etc.?).

Regardless, why would two 800MHz sticks show up as 667? Should the timing sequence also match?

Thanks.
EarthDog
10-30-09, 08:10 PM
Im not certain why they show up that way...sorry. my guess is b/c they are not matching sticks (as far as timings go). Try to manually set it to 800 with the 666 timings and see if that works.

As far as overclocking, not too many downsides when done properly... Let me link you a guide for AMD Phenom II chips (you didnt list what you have but know its an AMD).
ocuser001
10-30-09, 08:16 PM
I haven an AMD Athlon II X4 620 Propus, with Gigabyte MA-785GM-US2H
EarthDog
10-30-09, 08:18 PM
Here is that guide... :)

http://www.ocforums.com/showthread.php?t=596023
redduc900
10-31-09, 03:24 AM
Regardless, why would two 800MHz sticks show up as 667?
EarthDog already answered your question...
Try to manually set it to 800...
... but just to elaborate. With you current FSB (CPU Frequency) of 200MHz on a 3:5 FSB : DRAM ratio, the resulting DRAM frequency is 667MHz (as shown by CPU-Z). After first setting the Set Memory Clock option to [Manual], set the Memory Clock option to [x4.00] 800, which results in a 1:2 FSB : DRAM ratio.