Another PSU thread!

NightmareXX · 5 Nov 2008 at 09:50

Uninformative titles are the best, aren't they

Simple question regarding two of the same PSU's I bought from a competitor. They were £15 each and appear to be unbranded. They're rated at 400W with a suitable amount of amps on the 12V rail. The systems that they're running are my BOINC boxes.

System 1: single core AMD 1620LE or something like that and 3 hard drives.
System 2: Dual core AMD AM2 X2 4000, 1 hard drive and an AGP graphics card.

Firstly, I'm right in thinking that the PSU's aren't being put under any sort of load? I've got one of those watt meter plug thingies and both systems draw about 90W continious.

In relation to the above, is it then safe to say that the PSU's shouldn't be blowing up and taking anything out? I've had the systems running for a few months now and I've not had any problems so far although I don't really want one to blow up and take out some hardware either.

semi-pro waster · 5 Nov 2008 at 13:03

The PSUs aren't being put under any major load if your watt meter is accurate. Cheap PSUs will usually be built using inferior components and with (sometimes) inadequate heatsinks, however since the load level is so low it shouldn't matter too much. If it runs without a problem then I'd suggest just leaving it, you might well create more problems than you solve if you try to fix it.

beefybarn · 5 Nov 2008 at 14:00

I was using a 550 watt cheapo psu to power a amd 1800 1 gig ram 1 hard drive and a dvd drive, 2 weeks later it blew taking the motherboard and hard drive, my advice definetly change it.

mishima · 5 Nov 2008 at 14:16

The risk you can run when using cheap PSU's is that the above happens, they take everything out with them if they go. Usually when they are under load, but if you aren't going to be stressing the system very much it might be worth running the risk. It's usually worth the little bit extra even on cheap systems to ensure the backbone of the system has some confidence.

alex24 · 5 Nov 2008 at 14:21

Indeed, seen this happen a lot, working for a small PC repair business. Cheap PSUs do often take out at least the mobo if anything. Depends how much you value the machine. There's a good chance they'd be fine too though, it's really your call. Weigh up the value fo the machines against new PSUs. There are some half decent cheap ones on OCUK, have a look.

NightmareXX · 5 Nov 2008 at 20:57

Hmm well the CPU is at 100% load all the time as I run BOINC but that's it. I had a cheepy PSU running my AMD Athlon 2000 XP system for 3-4 years without a single problem and at the time, wouldn't have thought of the PSU as being a problem anyway.

As I'm home now, the ratings are:
12v - 18A
5V - 35A
3.3V - 28A
ATX 1.3 compliant

It's got a sticker on it saying that it passed a burn in test if that's anything good

I do value the system it's installed in however I'm not entirely sure that spending ~£70-80 for both systems together would be worth it.

The PSU is cold to the touch so it definatly isn't being overloaded.