letstalkcisco
Member
So I've been reading about OC'ing my AMD64 system for the past couple of months (including the 'guide to OC' forum post) and I finally assimilated enough info to try it for myself. I feel like I've had some success in adding another 400Mhz, however, there are still a few pieces I don't get and maybe someone can fill me in.
Stock system:
AMD 3700+ san diego
ASUS A8N-SLI Deluxe
mushkin 2-2-2-5 pc3200 512MBx2
xfx geforce 7800gt
So I first tried loosening all my RAM timings to 3-4-4-8 and maxed the voltage to both the RAM and the CPU (2.9 and 1.55 respectively). I dropped the CPU multi to x10 and raised the memory bus to 240Mhz and dropped my HTT to 4x hoping for a modest 200Mhz gain. No dice on prime95, and so went through various settings trying to get it to stabilize (eventually dropping below stock 2.2ghz). I ended up with CPU multi of 8x and HTT 3x and still no luck. So I tried to go in the other direction and left the CPU multi at 11x, HTT at 3x and set the memory bus to 240Mhz. Still failing prime95 but very close. I ended up with multiplier 11x, HTT=auto (no setting I tried seemed to make ANY difference) and memory bus at 237Mhz. This gave me 2.6Ghz, 948FSB and no problems after 10 minutes of prime95. I was able to lower the CPU voltage to 1.475v (lowered my CPU temp 8 degrees C) and tighten my memory timings up to 2-4-3-7. I'll run prime95 again when I go off to work to fully verify stability - it passes the five minute test so far.
So 2.6Ghz is pretty satisfying, but I don't understand why I'm not able to have a stable system with any multiplier other than x11??? Could it be that my $150 mushkin RAM is just a poor overclocker and doesn't do well with higher bus speeds? (I realize now I should've gotten OCZ platinum or something but I didn't know that at the time of purchase.)
I also don't get why my FSB is 800Mhz at stock speeds -- I read that your FSB is your HTT x Mem speed, and that it should always be less than 1000 on current systems. That doesn't appear to be the case given that no setting I put on my HTT makes any difference in my FSB rating. If it in fact IS what I thought, then it appears to be locked in at x4 regardless of my settings because my FSB rating (according to my asus utility) is ALWAYS 4x whatever I set my memory speed (4x237=948 in this case). Maybe this is totally obvious, but I haven't been able to figure it out.
My last question has to do with the BIOS setting "Memclock Index Value" which defaults to 400, which I assume correlates to DDR400. There are other settings in there like 333, 433, and so on, but I don't get how this factors into the grand scheme of OC'ing. I thought that your DDR rating was a derivative of other parts of the OC process rather than being an independent setting?
So the end result is my 3dmark05 score went from 7155 to 7249. I was kinda hoping for a larger jump, but I'll take what I can get.
So if anyone has any advice as to how I can squeeze more out of this setup, or even as to how my approach is fundamentally wrong in some way then I'll be very grateful. In fact I'll take anything I can get.
TIA
Stock system:
AMD 3700+ san diego
ASUS A8N-SLI Deluxe
mushkin 2-2-2-5 pc3200 512MBx2
xfx geforce 7800gt
So I first tried loosening all my RAM timings to 3-4-4-8 and maxed the voltage to both the RAM and the CPU (2.9 and 1.55 respectively). I dropped the CPU multi to x10 and raised the memory bus to 240Mhz and dropped my HTT to 4x hoping for a modest 200Mhz gain. No dice on prime95, and so went through various settings trying to get it to stabilize (eventually dropping below stock 2.2ghz). I ended up with CPU multi of 8x and HTT 3x and still no luck. So I tried to go in the other direction and left the CPU multi at 11x, HTT at 3x and set the memory bus to 240Mhz. Still failing prime95 but very close. I ended up with multiplier 11x, HTT=auto (no setting I tried seemed to make ANY difference) and memory bus at 237Mhz. This gave me 2.6Ghz, 948FSB and no problems after 10 minutes of prime95. I was able to lower the CPU voltage to 1.475v (lowered my CPU temp 8 degrees C) and tighten my memory timings up to 2-4-3-7. I'll run prime95 again when I go off to work to fully verify stability - it passes the five minute test so far.
So 2.6Ghz is pretty satisfying, but I don't understand why I'm not able to have a stable system with any multiplier other than x11??? Could it be that my $150 mushkin RAM is just a poor overclocker and doesn't do well with higher bus speeds? (I realize now I should've gotten OCZ platinum or something but I didn't know that at the time of purchase.)
I also don't get why my FSB is 800Mhz at stock speeds -- I read that your FSB is your HTT x Mem speed, and that it should always be less than 1000 on current systems. That doesn't appear to be the case given that no setting I put on my HTT makes any difference in my FSB rating. If it in fact IS what I thought, then it appears to be locked in at x4 regardless of my settings because my FSB rating (according to my asus utility) is ALWAYS 4x whatever I set my memory speed (4x237=948 in this case). Maybe this is totally obvious, but I haven't been able to figure it out.
My last question has to do with the BIOS setting "Memclock Index Value" which defaults to 400, which I assume correlates to DDR400. There are other settings in there like 333, 433, and so on, but I don't get how this factors into the grand scheme of OC'ing. I thought that your DDR rating was a derivative of other parts of the OC process rather than being an independent setting?
So the end result is my 3dmark05 score went from 7155 to 7249. I was kinda hoping for a larger jump, but I'll take what I can get.
So if anyone has any advice as to how I can squeeze more out of this setup, or even as to how my approach is fundamentally wrong in some way then I'll be very grateful. In fact I'll take anything I can get.
TIA
