266x12 Vs 400x8 780i, Qx6700

[cpsusie]

Hi guys,

 

I currently have an EVGA nVidia 780i, with q QX6700 processor overclocked from 2.66 to 3.2 by raising the cpu multiplier by 12. I have no problems with temperature or stability. For the longest time I thought my RAM was my bottle neck but I am beginning to suspect it's my FSB. I used to have 8GB of 5-5-5-15-2T, DDR2 Ram at 800Mhz and only got 5.3 on the Vista Experience thingy where everything else is 5.9. (I know that isn't the benchmark to go by but it raised my suspicions). So I decided to get some 4-4-4-12 800Mhz DDR2 Ram and was able to pick up 8GB for about 100 bucks. Guess what -- still 5.3. PLUS, I suspect I am not getting the framerates I should given my system (I have 2 9800GX2s in SLI).

 

I did a little research and it seems that my FSB is my bottleneck, not my RAM -- my ram isn't even as fast as my FSB. So, it occurred to me that I would be able to get 1:1 with my ram @ 3.2 Ghz (I have no desire to OC the CPU any faster than this) if I increased the FSB to 400 and decreased the CPU multiplier by 8.

 

My question is does anyone have the 780i and the Qx6700 running at 400x8? Since it runs fine at 2.66x12 can I expect it to probably be achievable at 400x8? Is there anything I need to know about OCing with the FSB vs. the CPU multiplier? I'm kinda nervous about it because I've never tinkered with the FSB before. Any advice?

 

Thanks,

Chris

[Waco]

You're going to be board limited when cranking the FSB on that CPU. I have my Q6600 at 400x8 and it works beautifully (and gets a 5.9 in everything except HDD speed).

[cpsusie]

You're going to be board limited when cranking the FSB on that CPU. I have my Q6600 at 400x8 and it works beautifully (and gets a 5.9 in everything except HDD speed).

 

If it works on the Q6600, do you think it will work on QX6700? Isn't the 6700 just a 6600 with a bit higher of a rating and an unlocked multiplier? Are you using liquid cooling? I am using Air cooling -- I have a Zalman heatsink and a bunch of case fans.

 

What board do you have? What are your CPU and FSB voltages set to?

 

Thanks,

Chris

[Waco]

You shouldn't have to change your vcore to run the higher FSB and lower multiplier. If anything you may have to raise your chipset voltage a notch or two.

 

I'm on air cooling with a DFI Blood Iron (P35 chipset). I see no reason why you couldn't simply set it at 400 MHz and x8 multiplier. Just make sure you set your RAM speed properly before rebooting. If it's unstable then you could at least try 333 MHz with a x9.5 or x10 multiplier.