Will OCing my E8500 push my PSU over the edge?

[SiliconX]

Hola.

After fighting tooth and nail with my new HD4870 cards in CF, finally got all the problems sorted out and everything is stable, so i'm going to start overlocking my E8500. Here is my current system:

Intel C2D E8500 Wolfdale (3.16GHz) with Noctua NH-U12P cooler (cores sitting at about 44C idle and this seems a little high so I might lap the HS and possibly the CPU)
Asus Rampage Formula Mobo (BIOS 0410)
8GB Mushkin XP2-8500 Ram (4x2GB)
2x Sapphire Radeon HD4870 in Crossfire (card BIOS's flashed to latest Sapphire BIOS)
SupremeFX II "onboard" soundcard
2x 150GB WD Raptor HDs (RAID 0)
500GB WD Caviar HD
Pioneer DVR-115D
PC Power and Cooling Silencer 750 Quad PSU (5V@30A/12V@60A/3.3V@24A/750W Cont/825W Peak)
Antec 1200 Case with 3*120MM intake/1*120MM side intake/2*120MM rear exhaust/1*200MM top exhaust)

From everything i've read on various forums and tech sites, this PSU should be just fine running my system. But once I start pushing my CPU (not to the limit, just want to hit 4GHz or a little above) and OC my GPUs a bit, would this PSU start to be the weak point? How much extra draw will overlocking put on my system, assuming the OC is to a point where the voltage increase isn't drastic? Local PC shop has alot of PSUs in stock that I can go for if need be (Thermaltake, Corsair, FSP, Silverstone, Antec).

Thanks for any advice.

 

[richardscott]

hitting 4ghz wont add to much load you can always teset it generally your gfx cards will moan first if there isnt enough power, expect to double the power of your cpu if you really push it, but i rekon ud be fine, if it is unstable unplug one gfx card then try again.

 

[SiliconX]

Yeah, I always overclock slowly but surely, and if it looks liek it can't keep up, that's fine. Just I kind of have everything installed "not permanently" so if I was to replace it, now would be the best time as i'm going to want to make sure i've done the cable management properly before I start overlocking.

Thanks for the reply!

 

[modtech]

I have the same Power supply and motherboard but with an E8400 and a 8800GT. 4870 are incredibly power hungry. Can't you just buy one of those kill-a-watt devices and measure the power draw over load, also the fan speed of the power supply increases proportionate to the load so if it's getting loud you may be near the edge. 4GHz works wonders if you have that much graphics power.

 

[SiliconX]

Hmmm, good point. I'll look at getting something to measure the load.

 

[orangegator]

According to the extreme power supply calculator, you should be fine. I plugged your system in and got 544W. That's not with the gpus overclocked, however, that will likely add 100W max. Your psu has a 60A 12+rail, with gives 720W. Should be plenty.

 

[SiliconX]

Ah, thanks for the link dude. Never knew about that.

Ran Prime95 Small and Large FFT and CPU cores on RealTemp topped out at 42C (cores were always within 1C of each other) so seems like a pretty good base to start from.

Only unfortunate thing is the absolute trash thermal dissipation on the NB/SB of these earlier Asus ROG boards (unless it hasn't changed). Reboot and enter into BIOS, NB/SB temps read about 60C/55C respectively. If I was a brain surgeon, i'd remove the whole heatsink assembly, lap the important parts and re-attach it with some AS Adhesive.

Have to look into some fans that will plop onto there I guess. Because that's way too hot for idle.

 

[modtech]

Just remember that not only are power supplies not 100&% efficient but their efficiency also decreases as they age and in general use with increased temperatures.

Asus used different/better paste on Rampage Formula, all you really need is to check that it's tight enough and get some air flow over the heatsinks in the correct manner. You might also want to check your NB voltage as X48 need so much less voltage than the bios dishes out on auto that it's almost funny.

 

[richardscott]

efficiency may drop but max load power will not just meant it sucks more out the wall than it did before.

 

[anartik]

According to the calculator you might need 544w but I really don't think, based off what I have seen of it, that it takes into account full load conditions for all the devices. According to the calc my new system was well served by the Antec 550w I had. The capacitors screamed a high pitched harmonic which would sometimes come out the speakers. I just about went deaf the first time it happened and the volume was turned up a bit. Age of the power supply also plays a big role as capacity drops off rapidly with age. I replaced it w/ a corsair 1000 which is an overkill but it had the quality along with the modular cables I wanted. The original system had a Rampage formula X48, E8500 @4.1, 2x WD640 HD's, overclocked 8800 GTX, 2 x DVD burners, soundblaster XFI and 2x120mm 2x80 1x92 fans and a slot cooler along with a number of USB powered devices. With the new PS the noise is gone, and I have gotten the system stable up to 4.37. Here shortly 2 more RAID 0 and a 4870X2 will get installed. I also got a different case and added more larger fans. Theres something to be said for having more headroom in a PS. Lower load and it runs quieter and cooler with fewer fluctuations. Also as it ages it will maintain a usable capacity for quite some time. That old Antec 550 got put in the old case with an Athlon X4400, A8N32SLI, Radeon X1900XT, soundblaster, a couple drives and it works just fine so it's not just age.