Vengance 1600 vs Dominator 1333? overclocking possibilities...

[mikeyw]

Hi,

I have a bit of a dilemma as to what memory to use. I have both here and am going to send one set back soon.

Corsair 1333 MHs Dominator (3x2GB)
Corsair 1600 MHz Vengance (3x4GB)

Obviously the Vengange looks better in every way but my motherboard doesn't support 1600 MHz, only: "Support for DDR3 2200/1333/1066/800 MHz memory modules"

When I put the vengance in, two sticks run at 1333 and the third is at a higher speed. I don't know if this affects performance, but I thought it might be bad to keep it so now I am running the dominator.

However since I have overclocked my i7-950, the memory might be affecting my efforts. I noticed with a BCLK speed of 166 that the maximum I can clock the CPU is 3.9GHz.

If I try 200x20, the memory speed is changed and I don't know if it's a bad thing to make it higher than its rated value.

However, the vengance is marketed as overclockable- do you think I can make it go to 2200 MHz (the next step above 1333 for the motherboard) to achieve a good overclock? (memory multiplier, 10, BCLK = 220, cpu multiplier 19 for example)?

Are there things I am not considering?

Thanks for any help for a newbie

[redduc900]

Obviously the Vengange looks better in every way but my motherboard doesn't support 1600 MHz, only: "Support for DDR3 2200/1333/1066/800 MHz memory modules"
Without knowing which board you have (I'm assuming it's a Gigabyte), but going by what you quoted above, the board supports up to DDR3-2200 RAM. Gigabyte for whatever reason leaves out DDR3-1600 from their memory support list, but that speed RAM will work just fine w/ your X58. In order to hit a DRAM frequency of 800MHz at a default BCLK of 133, the DRAM multiplier (System Memory Multiplier (SPD)) will need to be set to x12 (133 x 12 = 1600; 2:12 BCLK : DRAM ratio).

[mikeyw]

Sorry, you are correct, it's a "Gigabyte SKT-1366 X58-USB3 Motherboard"

So what you are saying is the motherboard will run it at 1600MHz but I must force this by manually setting the memory multiplier? Thanks.

If I set the memory multiplier to 12, that still limits my overclock to 3.9GHz, because the highest CPU multiplier I can use is apparently 24. I was wondering if I can try increasing BCLK to increase the CPU frequency, without causing problems with the RAM?

[redduc900]

So what you are saying is the motherboard will run it at 1600MHz but I must force this by manually setting the memory multiplier?
Yes
If I set the memory multiplier to 12, that still limits my overclock to 3.9GHz, because the highest CPU multiplier I can use is apparently 24. I was wondering if I can try increasing BCLK to increase the CPU frequency, without causing problems with the RAM?
I just gave you an example of what the DRAM multiplier would need to be set to in order to run the RAM at 800MHz w/ the BCLK at the default of 133. That's not to say that the BCLK, DRAM multiplier, or CPU multiplier can't be changed. Disable Turbo for a locked x23 multiplier (lower multipliers will still be available), and set your goal for 200 BCLK x 20 = 4.0GHz, this w/ the DRAM multiplier at x8 = DDR3-1600. And for a more thorough explanation you should check out Miah's overclocking guide for the Bloomfield here...

3 Step Overclocking Guide – Bloomfield and Gulftown
http://www.techreaction.net/2010/09/07/3-step-overclocking-guide-bloomfield-and-gulftown/

[mikeyw]

Thankyou! I'll try those settings and read that guide whilst testing the stability.