Help a Computer Noob With His GPU & PSU?

[Jim Raynor]

I've done a lot of research online and have read through similar threads on this forum, but as a total noob I'm still not confident that I understand everything that I should. Can somebody help me out with this?

I have a HP Pavilion a6857c computer that I bought in late 2008:

Motherboard: Pegatron Corp Benicia 1.01
Chipset: Intel(R) G33/G31 Express Chipset Family
Processor: Intel(R) Core 2 Quad
CPU Speed: Q8200 (2.33 GHz)
RAM: 8 GB
Power Supply: 300W

Apparently that's more than enough to run the games that I want, except for the crappy graphics unit. So I recently bought a NVIDIA GeForce GTX 460 graphics card, which I think is compatibile with my computer after doing extensive research including learning about a bunch of things for the first time. Someone tell me if it isn't compatible.

Anyway, like I said I think the GeForce will work on my computer - except for the fact that it states a minimum requirement of 450W of power, and my computer is currently at 300W. So I took a look at some power supplies, such as Corsair's 650TX or 750TX. The 750TX is $20.00 more than the 650TX, but I'm more than willing to pay that if it's necessary or will be necessary in the next couple of years.

But after reading some computer forums and talking to some people (who all may or may not be full of shit), I've heard some horror stories about power supplies. Such as the need to measure the inside of your computer to see if the thing will even fit, and how some power supplies might be "too powerful" and burn out the motherboard. So if you're still with me (thanks for reading this far), I'd like it if you could inform me about what I should be concerned about. What kind of things affect PSU compatibility, or should all modern, mainstream, big-name computer and power supply brands basically be compatible? Does the Corsair 650TX or 750TX look like it'll work on my computer?

[atg]

Such as the need to measure the inside of your computer to see if the thing will even fit,

Some cases will only take a 'slim-line' PSU. Based on a quick look at your model, it seems to just take a normal one.

and how some power supplies might be "too powerful" and burn out the motherboard.

Yeah that's bogus.

So if you're still with me (thanks for reading this far), I'd like it if you could inform me about what I should be concerned about. What kind of things affect PSU compatibility, or should all modern, mainstream, big-name computer and power supply brands basically be compatible? Does the Corsair 650TX or 750TX look like it'll work on my computer?

Buy a brand name and you can't really go wrong. My personal choice is Antec. I havn't used Corsair PSU's personally, but I havn't heard anything particularly bad about them. A 650W should do plenty for what you need I would think.

[Sriad]

and how some power supplies might be "too powerful" and burn out the motherboard.

Yeah that's bogus.

Almost totally right, but it would be more correct to say "that's a misunderstanding of a real problem."

Certain (shitty) manufacturers sell inexpensive PSUs that claim very high numbers but can fail catastrophically if the consumer tries to use them at that level. In some cases when they fail they can more-or-less destroy an entire system. It isn't an issue of a PSU being "too powerful"-- you could stick a 1200W unit in there and as long as it's from a reputable manufacturer it'll be fine. Corsair and Antec are both fine.

[Phantasee]

Everybody who has given me advice has recommended to go for slightly more power because the PSU will last longer (so if you're using 400W of a 650W PSU, you're using it at 62% of capacity, but using 400W of a 750W PSU means you're using 53% of capacity). I don't remember what the optimal percentage is, though. Phongn is the one who told me that, IIRC.

[atg]

Certain (shitty) manufacturers sell inexpensive PSUs that claim very high numbers but can fail catastrophically if the consumer tries to use them at that level.

That's just a crappy built PSU - nothing to do with 'too much' power going to the motherboard...

Everybody who has given me advice has recommended to go for slightly more power because the PSU will last longer (so if you're using 400W of a 650W PSU, you're using it at 62% of capacity, but using 400W of a 750W PSU means you're using 53% of capacity). I don't remember what the optimal percentage is, though. Phongn is the one who told me that, IIRC.

I don't thinks its a case of it necessarily lasting longer, just that PSUs have their most efficient use of power somewhere in the 65-75% range IIRC.

[Jim Raynor]

Thanks for the help guys.