FSB:RAM ratio with Q6600

Langiroth

Distinguished
Sep 5, 2008
1
0
18,510
For reference, here is my build:

Q6600@3.0 | EP45-DS3R | Mushkin 4GB DDR2-800 | 4870@770/1080 | 500GB HDD | Corsair HX520W | Samsung 216BW | G15, G5

According to CPU-Z, my DRAM frequency is at 500 MHz at the moment, but I'm running my Q6600 at 333x9. I want to maintain a 1:1 FSB:RAM ratio.

1) Why is it at 500 MHz? Isn't 400 MHz the maximum for DDR2-800, or is this the effective clock? Even if so, shouldn't it be at 800, not 500?
2) Assuming I get the RAM speed worked out, would it be better to underclock the RAM to 667 to run it in sync with the Q6600 @ 333x9, or would it be better to overclock the CPU to 400x8 (no way am I hitting 400x9 on a Freezer 7 Pro) and have the RAM at stock speeds? This is purely in terms of stability, not performance, since I imagine the performance difference between the two is negligible.

Thanks for any answers!
 

doomturkey

Distinguished
Sep 18, 2005
430
0
18,780
If you want to maintain the 1:1 ratio, then you would be underclocking your RAM to DDR2 667. You have to change the ratio in the BIOS, its pretty simple. I currently have my Q6600 at 400x8, just because its a nice simple number instead of 356x9. Plus, it syncs my RAM with FSB. I doubt you will have stability issues as long as you have enough voltage on your CPU and your RAM is running at or under stock.
 

faster3200

Distinguished
Sep 4, 2008
287
0
18,780

Ok, I am not sure how much you understand about ram so if this seems basic then you are right. Since you are running at 333 fsb but your ram is at 500. That means that you have a divider set, which I believe is defaulted to on for for most mobos now. Since this is the number CPU-Z is reporting this is not the effective speed the ram is running at. Since we are talking about DDR (double data rate) you need to double the fsb speed to get the effective speed the ram is at, which would be 1000mhz, a fairly decent OC. I am not sure what your mobo bios will call it but look for a setting that has 1/1, 2/3, 5/8, and similar and set that to 1/1. Then you will have a 1:1 ratio and an effective mem speed of 666mhz.


Well 333x9=3.0ghz vs. 400x8=3.2ghz so, you will see improvements regardless of ram speed. Personally I would rather use a 9 multi since it will be easier on on your northbridge. Ram speed doesn't make a drastic difference with C2D or C2Q in terms of performance unless you are doing something really ram intensive (not gaming).
 

iluvgillgill

Splendid
Jan 1, 2007
3,732
0
22,790
it really depend on what's your target overclock speed. if its 3.2Ghz its best to select 8X so you can get great overall system bandwidth which will benefit many parts in your system. but if its 3.6Ghz then select 9x multiplier.

when you ask about DDR2-800 can only go up to 400FSB@1:1, it actually can run as high as its ability allows. the ddr2-800 is RATED guarranteed speed by the manufacture. anything higher will depend on your luck!thats what overclock mean.
 

V3NOM

Distinguished
Jun 18, 2008
2,599
0
20,780
hey gill if my mobo supports half multipliers (eg 7.5x), does the Q6600? or is it to do with the cpu and the mobo doesnt matter?
 

iluvgillgill

Splendid
Jan 1, 2007
3,732
0
22,790
firstly the mobo must support the newer CPU who has 0.5x multiplier in it. but if a CPU that has no 0.5x multiplier then it wont show in the BIOS as a available adjustment.
 

V3NOM

Distinguished
Jun 18, 2008
2,599
0
20,780

pity I'm a big young to have a "wifey" :kaola:
:love: :love: :love: :love: :love: :love: :love: :love: :love: :love: :love: :love: :love: spammmmmmmmmmmm

 

V3NOM

Distinguished
Jun 18, 2008
2,599
0
20,780
^AHAHAHA. yeah pity that :( why can't there be models and stoff at overclocking competitions! if they like going to race days with extreme cars, why not extreme comps! :(