ASUS Overclocking

[BradyT88]

I have been working on overclocking my computer. It is an ASUS M4A785-M, a PhII 925 x4 2.8GHz 95 watt, with a corsair H50.

I have a few questions about some of my bios options and such. I underclocked my cpu and memory (isolating the NB/HT) and started turning up my reference clock to see how high my HT Link/NB Freq can remain stable. I got it to run stable for an hour of Prime95 at 263MHz with x10 multi'sat stock voltage. Turning up the HTT over voltage from 1.2 to 1.245, I got 265MHz to run stable for 2 hrs of Prime95 blend. Does this mean that when I am overclocking everything together that I won't have to worry about turning down the HT multi until I break the 263/265 barrier?

I haven't been able to find much at all about VDDNB voltage. It is an option in my bios. I'm not sure what it is by default, as it says it varies by CPU, but I can set it anywhere between .9 to 1.55 volts in .00625 increments. Also what do you recommend I do with this to improve my OC.

What do you guys think about Loadline Calibration? I have left mine on auto, which puts it at 53%. I have read that you should probably turn this off as you start getting to the max voltage of your CPU as it causes voltage spikes.

Should I leave CPU prefetching enabled?

I have heard that Advanced Clock Calibration is for unlocking cores, but since I am already running a Quad core is there any benefit to enabling this?

Sorry this is so long. I just wanted to try to get as good an OC as possible (me and everybody else, haha) and I didn't know enough about some of these other options in my bios. I had my reference clock run stable for 2 hrs at 265MHz (1.5v) doing small FFT's with my HT and RAM underclocked (CPU isolated). I haven't been able to get 270 to not BSOD though.

Thanks for all your help.

 

[BradyT88]

I'm somewhat disappointed... this thread has been up for almost 20 days now and not a single response yet

 

[Brutal-Force]

to the forums.

I am sorry no one has been able to answer your question. I am an Intel guy so I really can't help with settings, but I can welcome you.

If you manage 2 hours Prime stable, then bump it up a notch. As long as your temps remain under their max, you still have headroom. Once you have reached a point where Prime is "barely" stable, bump it back a notch and at that point try to see if you can get 24 hours prime stable.

Leave prefetching enabled. Leave load line calibration enabled. It limits Vdroop which is when the voltage drops off while under load. Although...... on AMD that might be different since Vdroop is an Intel thing. Watch your voltages in CPUz and see if the voltages change. If they do try enableing it and see the difference.

 

[jazon1]

same goes for me,i haven't messed with an amd in some time,other than the FX series i never really had any luck with them overclocking well for me.but good luck in your endeavors and sorry no one has been able to answer your question with any authority yet.but what brutal said sounds right to me.

 

[BradyT88]

Thanks for your responses. My OC hasn't been going too bad so far. I am actually running P95 small FFT right now with my CPU at 3.78GHz (270x14) @ 1.55v. I've heard the Phenom's like it cooler, and since it is winter here in Idaho I was worried that I might get stable now and then run into issues when it warms up in the summer. well lucky for me this OC mixed with an H50 makes an excellent heater. My room is sitting at about 38C and my CPU hasn't broke 52C after 2+ hours of stressing I'm hoping to get 3.8 stable and I think I will be happy with a whole 1GHz increase over stock.

 

[jazon1]

lol yea i hardly need a heater in my office between the pc a 42"lcd and xbox 360 and a ps3,its a ***** to keep cool in the summer tho,have to run the AC non stop lol

 

[BradyT88]

Well 270x14 was stable for 3.5 hours of P95 so i am moving on to 275. If this runs stable, I will move on... The problem is that when I was testing how high I can push the reference clock, 278 worked fine, but 279 would BSOD every time. What to I change to improve that?

 

[jazon1]

278 could just be as far as your mobo and cpu can handle stable at your current settings and voltages,i mean you could always up your voltages more but dont go over the max recommended for your setup,or you might fry something i wish i could be more help but i haven't overclocked anything amd in ages.i just retired my asus crosshair w/6400+ but i never even bothered with OCing it

 

[BradyT88]

Well I ended up with 275 failing, but I got 278 with the CPU, HT/NB, and Memory severly underclocked.

 

[Neuromancer]

ASUS boards in my experience are not very good for HTREF clocking. At least the two I had/have were not.

255 was the most I could get on a M4A79 Deluxe and 300 on the CHIII (I'm not even talking 24/7 stability, I mean benchmark stability)

 

[BradyT88]

Well it won't be a problem unless I can find a way to get my cpu stable without raising the vcore. 275x14 and 273x14 and 272x14 failed. I haven't tried 271 yet, 270 was stable though.

If 1.55v is the safe limit for the vcore think I could push it any higher since I am water cooled. My temps have yet to break 52C and that was with my room boiling hot. I was sitting in my room on my laptop and it got so hot it actually freaked out it and started lagging really hard and I was sweating just sitting in the room.

 

[QuietIce]

I'm somewhat disappointed... this thread has been up for almost 20 days now and not a single response yet

Sorry, I usually don't visit the motherboard section - just the AMD CPU section.


270x14 isn't bad at all for a 925!

I've had nothing but good luck with my ASUS boards. I also tend to buy the high-end units but the ones Neuromancer mentioned are high-end. Mine are also at least a year old with a different SB, maybe that's the difference.


Anyway, are you keeping track of your cpuNB, HT Link, and RAM speeds? At 270 MHz you might want to run 8-9x cpuNB, 5-6x HT Link, and well I can't tell on the RAM (depends on what you've got). cpuNB VDD is standard at 1.175v and most run it 1.225-1.250v when OC'ing - sometimes more ...

 

[BradyT88]

Yeah. I can run the CPUNB stable t 270x10 but the HT Link is at x5. My Ram is killing my OC as it some cheap Corsair DDR2 800, I am working on replacing it with some DDR2 1200 though