Overclocking Escapades: socket AM3 Phenom II X4 965 Black Edition

[Tech Tweaker]

Well, I've owned this Phenom II X4 965 Black Edition processor for probably at least two years now I'd say. I figured it was about time I tried my hand at overclocking it.

So, since I just had an AM3 board come in earlier this week I thought I would see what it could do. Dolk's guide was quite helpful in this process, so thanks to him for writing it.

Going up to 3.8GHz was easy enough, I just increased the voltage to 1.425V in the bios and it was stable pretty quickly.

Four Gigahertz is proving elusive though, as so far the system just wants to either black screen, shut down and reboot itself within 30-40 seconds of starting Prime95 blend, or blue screen and reboot. It seems that may have been caused by not enough voltage to the CPU Northbridge (which I'd never heard of), as I was only giving it the stock 1.1V, and apparently for the multiplier I'm at (x12 IIRC) 1.25V is what is recommended. I haven't yet tested 4.0GHz for stability after having realized my mistake with the CPU NB voltage.

I'm currently working on 3.9GHz at 1.5V for the CPU. I know that might be too much, but I'm testing for stability and working my way down on the voltage. If it's stable at 1.5V, I'll then lower to say 1.475V and test again. I will of course then continue the process until I find the minimum stable voltage.

I must say that this CPU puts off an awful lot of heat. It's like I'm trying to cool an active volcano with a simple heatsink and some fans. Codename "Dragon" seems appropriate, as it's certainly as hot as the breath of something the breathes fire.

I had one of my Thermalright Ultima 90 heatsinks' on it earlier, and I was hitting 60°C within 30-40 seconds of starting Prime95 blend. I was also able to put my hand behind the heatsink and easily feel very warm air coming off the rear pull fan (and warm my hands up with it). Of course that wouldn't do, so I did a minor tear-down and replaced the Ultima 90 with an Ultra 120 Extreme and a couple of Cooler Master SickleFlow Blue LED fans. I've also had to break out a couple of fans to cool the heatsink/heatpipe for the mosfets and Northbridge.

So far, the TRUE is cooling it considerably better than the Ultima 90, as I am so far topping out at 50°C, which is considerably more manageable. Though I've now had to open a window to let the cool air in (it's 26°F/-3°C outside), so that I can keep the room around 70°F/21°C.

 

[keny]

I would leave the CPU NB at stock until you have maxxed out the CPU clock, it makes it easier to find the cause of the bsod if only the CPU is being stressed. I do the same as you, start at 1.5v vcore everything else at stock, hr at 1600, CPU at x20 and go from there

 

[Johan45]

Cooling is the key for those CPUs, I found that once mine got to 55c + it would typically cash when I was going for the 4.0. I never did get it stable on air with a hyper 212. I just couldn't give it enough volts. Once I put it under water 4.0 at 1.51v was not a problem. If you're following the guide you should have the NB around 2600+, it really does work.

 

[Tech Tweaker]

Well, managed to get the CPU vCore down to 1.475V and that was stable for a 3 hour test on Prime95 blend.

Going to see if I can get 1.45V to work next.

Here's some informational pics from my setup, finally. I kind of forgot to upload those at first. Ambient temp is 78°F/26°C at time of screenshot, for reference. It's hot in here today for some reason, going to have to open a window to get these temps down as it's getting a bit uncomfortable in here.

 

[Johan45]

Looks good! That wasn't under load was it? The HWmonitor shot I mean.

 

[Tech Tweaker]

Looks good! That wasn't under load was it? The HWmonitor shot I mean.

No, that was just idle with CPU-Z and Hardware Monitor open.

 

[Mandrake4565]

Tech Tweaker, from what I've seen with the 965's and Johan can attest to it, seem to take a lot more voltage clock for clock compared to the 955's. I found with my 955 in order to get it stable at the higher OC's it helped raising the NB slightly and my best performance for a 24/7 OC was with it in the 2600 area. Additionally, I was able to get mine stable 2 hours prime on air @ 4.0 with the Ram at near 1700 Mhz again with the NB at 2600 ish. Though I have a pretty good 955 and as you know it's just a silicon lottery.

 

[Tech Tweaker]

Well, 1.45V was definitely not stable. The system blue screened and rebooted about 30 minutes into testing.

 

[Mandrake4565]

Well, 1.45V was definitely not stable. The system blue screened and rebooted about 30 minutes into testing.

The 965's definitely seem to like voltage.

 

[Tech Tweaker]

Well, I'm at 4GHz now with 1.55V (anything less wasn't remotely stable in Prime95).

Seems like a water cooling setup might be a must for 4GHz or greater, as this thing is running hot at 4GHz. It seems like I'm getting close to the thermal wall, as I'm hitting 53-54°C under load (Prime95) within a minute or two with fairly normal ambient temps (74°F/23°C), and then the system crashes in Prime95 at 1.525V to the CPU (even though it seems stable doing everything else).

Had to open a window and set up a fan blowing cool outside air into the room to get ambient down to 68-70°F/20-21°C so that I could get the max temps down to 50°C (so far).

 

[Johan45]

I was having the same issue on air seemed fine untill the temp got to the higher 50s then it just crashed

 

[Mandrake4565]

tech, what motherboard are you using?

 

[Tech Tweaker]

tech, what motherboard are you using?

A Gigabyte GA-MA790XT-UD4P.

 

[Mandrake4565]

A Gigabyte GA-MA790XT-UD4P.

Ok I was thinking that this problem may be caused by a weak Vrm section

the system crashes in Prime95 at 1.525V to the CPU (even though it seems stable doing everything else).

But that shouldn't be the case with that board.

 

[Tech Tweaker]

The system also crashed at 1.55V. I set it to run and walked away after ten minutes or so and came back an hour or so later and it had rebooted and was just sitting at the desktop doing nothing. Seems I may need 1.57V or greater for 4GHz.

I'm unsure on exactly what the safe voltage limit for Deneb-based processors is though.

 

[Mandrake4565]

Safe for what? Running it daily or benching. I wouldn't run even 1.5 for a daily OC for benching that's a different story.

 

[Tech Tweaker]

Safe for what? Running it daily or benching. I wouldn't run even 1.5 for a daily OC for benching that's a different story.

Just benching at this point.

Safe as in not kill it immediately.

 

[Mr.Scott]

It's all about cooling on these processors. 55c = unstable
Need to be below 50c for best results. Water is almost a must. Max Vcore for 24/7 on good cooling IMO is around 1.55v pending your load temps. For benching, sky's the limit, again, pending your load temps. Your board is more than ample for the task. You have a piece of average silicon. 4 gig will be tough.

 

[Mandrake4565]

It's all about cooling on these processors. 55c = unstable
Need to be below 50c for best results. Water is almost a must. Max Vcore for 24/7 on good cooling IMO is around 1.55v pending your load temps. For benching, sky's the limit, again, pending your load temps. Your board is more than ample for the task. You have a piece of average silicon. 4 gig will be tough.

I agree with Mr Scott, I don't have a problem pushing volts into my Cpu's but I will not do it at high temps. I have run my 955 at near 1.6 cpu at 46XX mhz for a 32m run on 2 cores and the temps were in the mid 40's during the run. I wouldn't have tried it if they were higher. When I switched over to my sub ambient watercooling, ie hanging my radiator out the window this winter I was able to put the 955 over 5.0 with 1.7 Cpu v that was with the water at -6c. I don't think the cores were above 10c while doing that.