Bottleneck?

[Guest]

Eh, there's some on YouTube I'm sure, never used guides personally. I've been overclocking and tweaking since Thunderbirds came out.

 

Now for some personal tips? I can do that.

 

Your motherboard uses the P45 chipset, which is a superb late model with a neat feature. This feature is the ability to unlink your RAM bus speed from your CPU bus speed settings. You'll find an option in your BIOS labeled "CPU:DRAM Clock Ratio" (located on page 24 of your manual, which is available http://www.foxconnchannel.com/ProductDetail.aspx?T=motherboard&U=en-us0000394 for your convenience) and this has several options including "Auto" and "Disabled". So if you set it to Disabled you can now overclock your CPU independently from your RAM and achieve a much higher clock speeds without hitting a RAM limit. Or you can keep it at 1:1 and your RAM will ramp up with your CPU, it's okay to do this but you're much more likely to hit a stability wall very quickly.

 

DDR2 RAM isn't meant to run at high speeds like DDR3, what DDR2 has is nice and low latency (roughly half of DDR3) so even at 800MHz DDR2 can work quite well. Unless you have really high quality DIMMs I kind of doubt you'll get much past 1066MHz, and you may not even get that high either.

 

For your CPU you can use the FSB (Front Side Bus, located on page 24 as well, labeled "CPU Clock") to adjust your frequency and if you're lucky you can change the multiplier, but I don't think you can with the regular Q8xxx series IIRC. Moving your FSB up from the default of 333MHz will increase your CPU core clock (calculated using Core Multiplier x FSB Speed) but of course this will have another adverse effect. You'll need to up the North Bridge Chipset voltage (page 30, O.V. Configuration, labeled "MCH Voltage Control"), vCore voltage settings for your CPU (same page and section) and of course the "VRAM" setting for your RAM if you have played with the ratio and FSB for your DDR2.

 

Your Q8400 generally operates between .85v to 1.2v-ish depending on the workload. You'll need to keep an eye on heat output and try not to go crazy with the vCore values, keep it under 1.4v (Intel's recommended is 1.3625v) and keep it under 75C at 100% load. Use Intel XTU, AIDA64 or Prime95 to stresstest it for several hours to make sure everything is stable. You can use voltage offsets later to keep the power savings and idle downclocking abilities of SpeedStep but for now just keep it on manual and get everything where you like it.

 

Last tip: DO NOT do everything in one go. Pick a part and start small, bump the FSB by 10-20MHz at a time and test it for at least 20-30 minutes. If it seems stable boost it a bit more. If it blue screens bump your voltage by .05V-.10V. Keep notes on what you've changed and what order you did them in, you'll need them when something goes wrong.

 

*Edit. A note on DDR2, 800MHz operates at about 1.8V and 1066MHz is around 2.1V in general. So a 900MHz overclock should be easy to achieve using about 1.9V. Be gentle on the RAM, it's more sensitive and has less safety nets than your CPU.

 

*Another edit: Harrynowls guide to Core2 overclocking is excellent and contains even more info than I'll remember. http://linustechtips.com/main/topic/232325-lga775-core2duo-core2quad-overclocking-guide/

Awesome thanks for that ill look into it. 

[Guest]

Eh, there's some on YouTube I'm sure, never used guides personally. I've been overclocking and tweaking since Thunderbirds came out.

 

Now for some personal tips? I can do that.

 

Your motherboard uses the P45 chipset, which is a superb late model with a neat feature. This feature is the ability to unlink your RAM bus speed from your CPU bus speed settings. You'll find an option in your BIOS labeled "CPU:DRAM Clock Ratio" (located on page 24 of your manual, which is available http://www.foxconnchannel.com/ProductDetail.aspx?T=motherboard&U=en-us0000394 for your convenience) and this has several options including "Auto" and "Disabled". So if you set it to Disabled you can now overclock your CPU independently from your RAM and achieve a much higher clock speeds without hitting a RAM limit. Or you can keep it at 1:1 and your RAM will ramp up with your CPU, it's okay to do this but you're much more likely to hit a stability wall very quickly.

 

DDR2 RAM isn't meant to run at high speeds like DDR3, what DDR2 has is nice and low latency (roughly half of DDR3) so even at 800MHz DDR2 can work quite well. Unless you have really high quality DIMMs I kind of doubt you'll get much past 1066MHz, and you may not even get that high either.

 

For your CPU you can use the FSB (Front Side Bus, located on page 24 as well, labeled "CPU Clock") to adjust your frequency and if you're lucky you can change the multiplier, but I don't think you can with the regular Q8xxx series IIRC. Moving your FSB up from the default of 333MHz will increase your CPU core clock (calculated using Core Multiplier x FSB Speed) but of course this will have another adverse effect. You'll need to up the North Bridge Chipset voltage (page 30, O.V. Configuration, labeled "MCH Voltage Control"), vCore voltage settings for your CPU (same page and section) and of course the "VRAM" setting for your RAM if you have played with the ratio and FSB for your DDR2.

 

Your Q8400 generally operates between .85v to 1.2v-ish depending on the workload. You'll need to keep an eye on heat output and try not to go crazy with the vCore values, keep it under 1.4v (Intel's recommended is 1.3625v) and keep it under 75C at 100% load. Use Intel XTU, AIDA64 or Prime95 to stresstest it for several hours to make sure everything is stable. You can use voltage offsets later to keep the power savings and idle downclocking abilities of SpeedStep but for now just keep it on manual and get everything where you like it.

 

Last tip: DO NOT do everything in one go. Pick a part and start small, bump the FSB by 10-20MHz at a time and test it for at least 20-30 minutes. If it seems stable boost it a bit more. If it blue screens bump your voltage by .05V-.10V. Keep notes on what you've changed and what order you did them in, you'll need them when something goes wrong.

 

*Edit. A note on DDR2, 800MHz operates at about 1.8V and 1066MHz is around 2.1V in general. So a 900MHz overclock should be easy to achieve using about 1.9V. Be gentle on the RAM, it's more sensitive and has less safety nets than your CPU.

 

*Another edit: Harrynowls guide to Core2 overclocking is excellent and contains even more info than I'll remember. http://linustechtips.com/main/topic/232325-lga775-core2duo-core2quad-overclocking-guide/

Thanks heaps Ill look into that.