Overclocking an Opteron 144 on Asus A8N-E

[Misiowiec]

I?m trying to overclock an ADM Opteron 144 (1.8GHz), but I can get my head around some of the calculations. The processor can handle 2.7GHz, but then I have to play around with the HT, memclock and CPU frequency values and end up running the memory at 194MHz, or slightly below the 220-225MHz it can take (it?s Samsung 2 x 512Mb PC3200).

The problem is I don?t know how I got the memory bus to 194Mhz as I don?t understand what parts the HT, memclock and CPU frequency play. Last time I overclocked was waaay back in 1998 when I pushed a Celeron 300 but increasing the FSB to 100Mhz, beating the fastest processors (PII 450) in all the benchmarks. That was easy, and having PC100 RAM ensured I had no problems. Now I have three variables to keep track of and it?s, well, not as easy at first sight.

So, can anyone help me by suggesting what values I should use to max both the CPU and RAM, without breaking their limits? And even better, can someone explain how it works so can play around myself. Maybe there's even an overclocking guide which explains HT, memclock and CPU frequency.

Thanks!

 

[Shimmishim]

its easy. just keep LDT x HTT under 1000.

In your case use LDT of 3 and you are using HTT of 300 so 3 x 300 = 900.

with your ram...

since you're running 2.7 ghz or 9 x 300, your ram is forced to run a divider.

i'm guessing your divider option is set to auto.

it should be forcing your ram i bet to run with the 133 divider (or ddr266).

i'm not sure what divider options are on that board but my guess is 166 and 200 or ddr333 and ddr400.

since the ddr333 will make your ram run around 245 which is something your ram can't handle, you are forced to run the 133 divider.

edit:

if you want to run your ram around 225, your best bet is to download A64 tweaker and manually set the divider option to 150 which will set your ram at exactly 225.

 

[Regalk]

I am not sure if i could link to another forum in here. But do a search for AMD tweaker, and A64memfreq11 and start from there. I had the same issue and it took me weeks to understand how it works and how my A8N-E reacted to different timings. I have the Venice3000+ and really pleased with it - I was thinking about the opty 144 but I have changed my mind - not worth upgrading too frequently.
Good luck - the highest speed is not the key as it was a few years ago - the memory controller must be optimized as well as the cpu speed of course.
You almost have the same setup as me. I also flashed the GTO2 to X850 but backed down to the modded X800 since the Gpu was a lot hotter and artifacting at X850 (slower mem speeds) than at X800 - I am not complaining though since it still has 16 pipes and at 530/580 runs a lot cooler at 35C idle.

 

[Shimmishim]

Originally posted by: Regalk
I am not sure if i could link to another forum in here. But do a search for AMD tweaker, and A64memfreq11 and start from there. I had the same issue and it took me weeks to understand how it works and how my A8N-E reacted to different timings. I have the Venice3000+ and really pleased with it - I was thinking about the opty 144 but I have changed my mind - not worth upgrading too frequently.
Good luck - the highest speed is not the key as it was a few years ago - the memory controller must be optimized as well as the cpu speed of course.
You almost have the same setup as me. I also flashed the GTO2 to X850 but backed down to the modded X800 since the Gpu was a lot hotter and artifacting at X850 (slower mem speeds) than at X800 - I am not complaining though since it still has 16 pipes and at 530/580 runs a lot cooler at 35C idle.

actually.

for AMD A64 chips or opterons, highest clock speed > mem timings and bandwidth in most cases.

 

[Misiowiec]

Thanks for your replies! It seems I better get faster RAM to be able to run at e.g. 245 MHz - this should also add a nice performance boost. I'll see if I can't something on eBay, the Crucial Ballistix PC4000 look like a good and inexpensive choice.

Regalk - yes, we do have similar systems. I was lucky in that the flash to X850 XT PE proved without problems, but then I fitted a great Zalman VF700-CU combo which brought the temperature (and the noise) down from what it was at X800 speeds. Overall I'm very happy with the new toys.

Thanks again.