Currently my manufactured (i.e not built by me) desktop is causing me some troubles:
Sometimes, when I put something into the DVD drive, the computer resets. I've had similar things happen with other computers in the past, and they've all ended up breaking. As such, I'm not putting anything into the drive until I determine and fix the problem.
I think it's a PSU problem, but I'm not certain.
Working along this assumption, I've used the power calculator to try and figure out where the PSU isn't supplying enough power.
Having input all of the information that I know (and having guessed at some of the fields) I ended up with this information:
Minimum 401W, Recommended 500W, 3.3V 8A, 5V 14.8, 12V 15.1A
However, my current PSU is 500W, 3V 28A, 5V 50A, 12V 18A, -12V 1.0A, 5VSB 2.5A
Perhaps I'm misunderstanding the information, but it seems I'm bettering if not matching the requirements.
So, perhaps some of the information I typed was wrong. I had to guess at:
Motherboard (how do you determine if it's high-end or not?)
RAM (I have 2 sticks, but I don't know the type. Is there an easy way to find this out with handling them?)
Fan (I'm assuming it's case fan only, I can guess at how to measure it [the casing for the fan doesn't count] but how do I know if it's high performance or not?)
Also, once I've figured out what I need, I want to try and future-proof it (I'll want a new GFX card in summer, or september, but don't want to have to buy new PSU then aswell) - is there any good advice for ensuring this?
The PSU looks to a very cheap non-branded PSU to me. A 500W with just 18A total on +12V, but 50A (!!) on +5V just sounds plain weird to me.
If you want to make sure, get a real 500W PSU from some (online?) store where you can return it, no questions asked. The new PSU should have more like 30A on +12V combined, and be a brand (Corsair, Silverstone, whatever).
If you go by what some manufacturers want you to believe, than Watts is all that you need. Don't be fooled by this. You can have a 500w PSU (like yours) that only has 18A on the 12V rail (most important rating right now) and have a "Quality" PSU of 500w that has 34A on the same 12V rail(s). There is a major difference between the two. The one your got would normally sell for about $35 or so and the one that I'm talking about would be around $75-$100 or so. PSU's are a not marketed the way they should be. The PSU manufacturers should be held to a certain standard and then we wouldn't have these many PSU issues. I know that I'm preaching to the choir, but this is how I feel. Okay enough of the rant, back to your question.
I'd go with one of these PSU's that I've listed below:
Now any of these PSU's are quite a bit of overkill for your current rig, but will be ready for any SLI/Xfire setup that you should need in the future. If you don't do things too extreme than you could get by with a Corsair vx450w PSU that has 33A on the 12V rails and can handle any single GPU solution to date. It should last you long and generally runs around the $75 price range. This is where I'd start from at the least. I'd recommend going with the Corsair hx520w first, but if you can't afford it, than at least go with the Corsair vx450w PSU or even the Antec NeoHE 550w for about the same $. You can decide what you can afford, but I'd stand by any of the selections that I've listed here.
Regardless of [claimed] rating, a cheap PSU may not be capable of putting out what's on its label. Jonnyguru and other review sites have described the "spectacular" failures which have occurred with cheap PSUs, some when loaded to <75% of their rating.