Maximum PC

So I have a AMD Phenom II X4 920 (2.8GHz) overclocked to 3.2GHz. I had it at 3.36GHz and it was running really well, never crashed or anything. I didn't stress it out other than gaming, but it wasn't 100% stable I don't think because I had to lower the O.C. to 3.2GHz to get it to fold. Any higher than 3.36GHz and it would not be stable and crash during gaming.

Anyway, I have just been changing the bus frequencies, I think I have it set to like 235MHz right now to get my CPU to 3.2GHz. Anyway, what can I do to get my overclock even higher? Temps are pretty low, I have a Cooler Master Hyper N 520 heatsink on it, it idles at 30 C, gets up to low 40s C at load. Increasing voltages will let me push the bus frequencies higher right? How exactly do I do this?

Increasing the core CPU voltage will allow the CPU to run faster (and hotter).

There are other voltages to consider as well .. RAM, chipset, etc. .. each of which allow you to push those components are harder (and hotter).

Here's the thing, though: we don't know which part of your system was causing F@H to fail. When you push the bus, you're pushing the entire system. This is good, in the sense that it nets the most performance, but it also introduces the most points of failure.

As always, take things one step at a time. Start by increasing the core voltage to your CPU and run Prime95. Bump it up until you stop crashing out or your temps get uncomfortable high.

If you are temp limited before it stops crashing, odds are pretty good that your crashes are caused elsewhere. Going from 3.2 to 3.36 shouldn't require more than a 0.1 or .2v increase (at most), so if that doesn't help, the problem lies elsewhere.

At what speed is your RAM running? Is it within spec? If not, you might have to bump the RAM voltage instead .. or in addition to the CPU voltage.

You're entering the interesting part of overclocking. Anyone can bump their CPU a bit these days .. but to fine tune your OC for maximum performance and 100% stability requires a lot of testing and patience.

I have 2x2GBs of G.Skill DDR2 1066 RAM. Currently they are running on a x4 multiplier, so they are actually under their rated speeds, at 940 MHz. So hopefully that won't be a limiting factor when I start pushing it more.

Yeah and thanks for the advice. I was meaning to ask what I should use to stress test it, so Prime95 is good then? This all sounds good, it seemed like I had plenty of thermal overhead that I could use to bump up the speeds, so I am hoping I get get it up to 3.4 100% stable.

If your PC can run a full Prime95 test without failures, it is rock-solid.

Good luck! I'd offer more advice but I don't know much about current AMD systems ... so I can only offer general advice.

Yeah, just run Prime95. FYI, Prime95 doesn't end, so don't expect it to. Just run it for 24 hours, and if there are no errors, the OC is as stable as it can get.

You can read more about Prime95, how it works and why we use it on wikipedia

Ok, so I went into my BIOS and I can either set the voltages to manual or auto. They default at auto, and they say that in auto they will automatically increase when overclocking. So do they just do a poor job of increasing the voltages, staying on the low end when it does it automatically? Or when it is stable in auto mode going to be the highest I can get it on manual mode also?

Don't use auto! It does increase voltage as needed, but unfortunately it does this with no concern as to the health of the processor. You could kill the Phenom without ever touching the voltage if you leave it on auto. Set it at the manufacturer recommended voltage and OC it from there.