About overclocking...

[EtchMcB 1]

...and stuff.

 

Right. So, my system was what you see in my sig. A Phenom II X6 at 3.5GHz (stock was 2.8) - this OC has been stable in heavy use for about a month now. Also one 5770, etc. So, I bought and installed a second 5770 today - Crossfired it in, and booted up. My motherboard pitched a fit, saying: "Overclocking Error" and something about the settings. Hit "Ignore and start anyway" and the system boots. The Crossfire works, I boot up FSX, and am getting ridiculously higher frames than on one card (good old Crossfire). Out of interest, I then go back to Windows and casually look at the CPU; and it's been punted back to 2.8GHz.

 

Why would there be any reason for my board to undo the overclock? For the record, the clock was done through the BIOS, not through Gigabyte's EasyTune 6, that's not a good idea. Did adding the second card cause the BIOS to forget what the hell was going on?

[TechguyMaxC 516]

Just go back into the BIOS and re-apply the overclock. This happens from time to time. I have found it to be a common problem among Gigabyte boards especially, though I do like Gigabyte.

[EtchMcB 1]

Okay - tried going back into the BIOS to re-enter the last stable settings I had on the overclock (thank goodness I wrote them down). No. Board keeps halting on startup with the same error. I'm thinking the power supply isn't putting out stable enough power to do the overclock with a second 5770 in. And now a new problem has been introduced - the watercooler liquid temps have rocketed up from averaging 21-28 degrees while overclocked (based on load) to 35-40 degrees.....at the stock speeds. Something's not right here.

[TechguyMaxC 516]

I seriously doubt it's your PSU, unless it's a low-quality unit. If your temps are way up you may have an air bubble in the system or a loose mount. I'd check the mount first, then listen for gurgling sounds in the system.

[EtchMcB 1]

Got the temps down - it was the pump, it wasn't spinning properly (this is the first time that's happened, would want to watch that). Tapped it lightly, spins just fine and temps are back down again. As for the PSU - it's not a high end model, so I'd doubt its quality. I'm looking at one of the Corsair modular 80+ Bronze ones to replace it. Am told they're reliable.

[Ben Cap 89]

I'm looking at one of the Corsair modular 80+ Bronze ones to replace it.

 

The Corsair AX750 would be an excellent choice. I have an AX850. - It is by far the nicest PSU I have ever owned.

[EtchMcB 1]

Well, an update: I fixed the issue. Back up to 3.5GHz.

 

I'm ashamed to say (especially as I BUILT my KOSMOS rig) that it was a combination of bad power supply, ancient sound card...and an amateur mistake. I pulled the sound card, one stick of RAM (down to 12 now, not that that's anything to sniff at) and...discovered I'd installed the second 5770 in a PCI-E x8 slot (instead of the other x16 slot on the board). That was probably not helping matters at all. Anyway, moved the card (lost the sound card in the process; it's a dual-slot 5770 and the x16 is directly above the only PCI slot on the board), booted back up, and the board didn't complain at all. Back to where I wanted to be.

 

But still looking at the AX power supplies on your (and others') recommendations. Might need to expand in the future (faster and more RAM, higher overclock), and that looks like the best call.