Possible Power Issue?

[Techtu]

I'm just wondering if my PSU is actually enough for my setup? I've used the online PSU calculator, which says it's plenty but since I upgraded my GPU I've been unable to overclock to the usual limits. On the CPU I used to hit 4Ghz (Air cooled at the time) without any problem whatsoever whilst also hitting 940mhz core/2040mhz memory on my old GTX460.

Now I'm stuck with 3.5Ghz on my CPU and 950Mhz core/1350mhz memory with my HD7950.

[Aquinus]

How much voltage were you pumping through it and what were the temperatures like? Pushing your CPU too hard can degrade the CPU and not let it run as well as it did before.

[drdeathx]

Voltage calculaters are BS. You have to look how many amps the 12 volt rails put out and calculate how many amps the system needs to be accurate. PSU's with same watts DO NOT put out the same amps. Pushing a PSU over 90% is not recommended.

[Techtu]

Originally Posted by Aquinus

How much voltage were you pumping through it and what were the temperatures like? Pushing your CPU too hard can degrade the CPU and not let it run as well as it did before.

I've never had to push the volts on my CPU to be honest but I did my GTX460, I've only ever used such high clocks for benchmarking as for everyday use I do stick with stock clocks. Temperatures have never been an issue either I had it on a Xigmatek S1283 which made sure it never seen temperatures over 53 degrees even on the hottest of days benching.

[Aquinus]

Originally Posted by drdeathx

You have to look how many amps the 12 volt rails put out and calculate how many amps the system needs to be accurate. PSU's with same watts DO NOT put out the same amps.

+1:

The outputs for the PSU in his specs
+3.3V@25A, +5V@25A, +12V1@18A, +12V2@18A, +12V3@18A, +12V4@18A, -12V@0.8A, +5VSB@3.0A

Make sure you're not running too much on each rail. That also feels like a lot of small rails; 4 @ 18A?

[Jstn7477]

I have that same PSU and I was able to run a 4.4GHz i7-2600K, HD 7950 @ 1050/1400, 1.05v AND an HD 7770 GHz edition on it using a molex to PCIe adapter for the 7770.

How old is your PSU? I got mine used a while back and am unsure of how old it is, and the noise killer is broken (fan runs at full blast 24/7).

[Techtu]

The PSU is just past 2 year old now I think or coming up to 2 years either way it's not old, really. Why couldn't you run the 7770 using the 2x 6pin PCI-E connectors? nevermind... obviously not enough connections, had to get an adaptor

[brandonwh64]

If its the PSU I sold justin then its a sold performer from what I seen!

[Techtu]

I really don't understand why it would limit my overclocks now, even if it isn't my PSU any other thoughts to what it might be?

[drdeathx]

Originally Posted by Aquinus

+1:

The outputs for the PSU in his specs
+3.3V@25A, +5V@25A, +12V1@18A, +12V2@18A, +12V3@18A, +12V4@18A, -12V@0.8A, +5VSB@3.0A

Make sure you're not running too much on each rail. That also feels like a lot of small rails; 4 @ 18A?

That is why I prefer 1 big juicy rail.