Need help to tweak overclocked system, please

[alexlyf]

Hi guys,

Finally I have built my game rig (At last!!). Now I want to overclock the system to get the most out of it.

My computer is using the following parts:

Opteron 165
Corsair XMS Twins (2 x 1 GB) 3200C2
Asus AN8-E

I start with BIOS setting reference:
RAM setting is manually set to 2.5-3-3-6 (manufacturer recommanded values), voltage 2.75., Memclock index value = 400MHz (no idea what this is, but the BIOS auto default is 200MHz and with that my sytem crawl).
CPU setting manually set to 200MHz x 9, core voltage = 1.376V, temperature at idle is 36C

Without changing other settings, I managed to raise the clock from 200 to 220Mhz with no problem (230 will cause random hanging). If I increase that further to 240 MHz, Windows gets very unstable.

Now, by just using the stock heatsink and without increasing the core voltage (I want to do that as a last resource, the CPU temperature shown is already high enough), what else should I tweak in the BIOS? I haven't done anything changes to the RAM settings yet, how should I change them?

I am such a noob in overclocking the modern computer. My last experience in OC is my celetron 300A.

Cheers,
Alex

 

[Covered_in_bees]

Here are some good articles on overclocking to read:

THG Forum Sticky
Very detailed guide from Short-Media
Another very good guide from MadShrimps

 

[alexlyf]

Great readings there, Covered_in_bees. Thank you!!

I managed to OC my system to 2.4G (267MHz x 9) with HT multipler =x4. I am a little worried about the RAM since it is now running at 222MHz (267MHz x 333/400, that's how Asus present the memory clock divider).

Any advice to further OC?

Cheers,
Alex

 

[Covered_in_bees]

All those settings look good provided that the temps are ok and it's stable.

You can check if the memory is ok with memtest86+. Note that, with Asus motherboards, you should disable 'Legacy USB support' in BIOS. There seems to be a problem with the Asus BIOS' and memtest86/memtest86+ with errors caused on test #6 when this is not disabled.

Have you tested the overall system stability with Prime95 or similar stress test yet ? You should test both cores, so create 2 separate directories with the Prime95 program files and run each one.

If your temps are still well below the 55C threshold most ppl recommend, then you could try increasing vCore to get a bit more out of the OC. However, increasing voltages can/will reduce the life of the CPU. Saying that, small increases are generally considered acceptable, and can provide better OC results or improved stability.

With an Opteron 165, 1.4v-1.45v should be ok. However, if you do not want to risk this, or do not gain a significantly better OC, then it's not really worth it.

I had to increase my vCore a bit for stability, and managed to get 2.65GHz from my Opteron 170 with vCore at 1.39-1.42. My CPU idle is 40C and 49C under full load (both cores). Don't really want to take it any further as ambient temps in summer are quite a bit higher than this time of year.

 

[alexlyf]

Thanks again for the tips, Covered_in_bees.

I am now running stress test with two Prime95 and the core temperature is staying at 55 to 56C in the morning time. Is that acceptable? Actually if I run the test in stock clock, the temperature is not too far from what I am testing now. The room temperature here is about 25C and the motherboard temperature is showing 35C in the Asus montior program. Could the calibration of the temperature sensor on board is off?

System seems stable for the first 2 hours, will see how it goes in 24 hours. I may consider to back down the reference clock by a few MHz to lower the temperature.

Cheers,
Alex