Is this a good PC to try for GPU computing?

[xilman]

Originally Posted by Rodrigo

But I haven't taken the (what to me seem) major steps of changing a CPU or a PSU.

The reason for my question was that I wanted to make sure that I wasn't making too big a deal out of a PSU replacement -- maybe I was being too cautious and skittish. But putting the difficulty at a 5 and 6 (maybe even a 7 and 8, as you said) compared to the 1 and 2 of a RAM operation would definitely jibe with my impression.

And mine. I'd rate it at 3, or 4 tops if you need to loosen a disk from its mounting for easier access. Every PSU removal I've undertaken has involved noting which kind of plugs need to be removed from which sockets; undoing four screws and carefully manoeuvring the PSU out of the case. Inserting a new PSU is just the reverse operation.

Paul

[Christenson]

He's right....the major issues with my system build involved the CPU and heatsink, not the power supply.

[nucleon]

Originally Posted by Rodrigo

Just to make sure -- you had two 200W HP Slimlines each running a GT430 with no problems?

correct

How hot did it get inside the Slimline cases (CPU, etc.) when running those graphics cards? Did you use stock cooling?

Rodrigo

I didn't take temp readings sorry. I bought the machines off ebay for$100. So it was a bit of a gamble. Stock everything. The 430s run cool. Seriously no dramas. In 6months they were only rebooted when I lost power to my apartment. :)

Do eeeeet.... :)

-- Craig

[Rodrigo]

Originally Posted by xilman

And mine. I'd rate it at 3, or 4 tops if you need to loosen a disk from its mounting for easier access. Every PSU removal I've undertaken has involved noting which kind of plugs need to be removed from which sockets; undoing four screws and carefully manoeuvring the PSU out of the case. Inserting a new PSU is just the reverse operation.

Paul

Hmm, that doesn't sound so hard...

How about the process of selecting the PSU, though. This business of "single" vs. "double" rails is mysterious to me. I get the part about splitting the available power into separate lines vs. keeping it all together so that it can be allocated more efficiently -- but how would one know which kind the PC takes? Assuming that there's enough room inside the case and the connectors are the right type, can you put any PSU (single- or multiple-rail) in any computer, or not really?

Actually, the more I read about PSUs (http://www.overclockers.com/forums/s...d.php?t=548862), the more confused I get.

Rodrigo

[Rodrigo]

Originally Posted by nucleon

correct


I didn't take temp readings sorry. I bought the machines off ebay for$100. So it was a bit of a gamble. Stock everything. The 430s run cool. Seriously no dramas. In 6months they were only rebooted when I lost power to my apartment. :)

Do eeeeet.... :)

-- Craig

Very cool! (so to speak)

This is good to know and very encouraging, thanks.

Rodrigo

[lavalamp]

Originally Posted by Rodrigo

This business of "single" vs. "double" rails is mysterious to me.

There's nothing much mysterious to it. Basically some higher power PSUs split the 12V lines so that (theoretically) only some arbitrary maximum current can flow down each line. You can basically ignore this.

As long as you make sure the plugs match up OK and everything that should have a power plug has a power plug, it'll be fine.

Check the motherboard, it'll likely have a 24 pin ATX connector, and then optionally a 4 or 8 pin connecter too.

Check the graphics card you buy, depending on how much grunt it has, it might need a 6 pin, two 6 pin, an 8 pin, a 6 pin and an 8 pin, or even two 8 pin PCIe connectors. The PCIe 8 pin connector can look similar but is NOT the same as the 8 pin ATX 12V conector.

Aside from that, go for an efficient PSU, the higher the better. Not only does this save electricity, it means it runs cooler, so it's worth spending a little bit extra for it.

Even for a low power system, the difference in electricity cost between an 80% and 85% efficient PSU can easily be $20 / year.

[LiquidNitrogen]

Originally Posted by Christenson

He's right....the major issues with my system build involved the CPU and heatsink, not the power supply.

As having built over 200 systems personally, I would like to impart a few words of wisdom regarding power supplies.

Something that is not on most people's radar when it comes to the Power Supply Unit (PSU) is the so-called "signal to noise" ratio. If you have a 300W PSU and you are up in the 260-280W range most of the time, you are getting close to the point where noise in the signal will become a factor for long-term computations. It's like inviting mini-brownouts a few times per 24 hours.

If, however, you are in the 260W-280W range and you have a 650W PSU, there is a snowball's chance in hell noise will be a factor.

A higher wattage PSU also gives you the flexibility to upgrade without too much concern. Add a couple more hard drives, throw in a better video card, add multiple Blu-ray burners, no problem. With a lower wattage PSU, you have to "count up" the watts every time you want to add something (because you never remember what the total was from the last time you did it!)

[Rodrigo]

Originally Posted by lavalamp

There's nothing much mysterious to it. Basically some higher power PSUs split the 12V lines so that (theoretically) only some arbitrary maximum current can flow down each line. You can basically ignore this.

As long as you make sure the plugs match up OK and everything that should have a power plug has a power plug, it'll be fine.

Check the motherboard, it'll likely have a 24 pin ATX connector, and then optionally a 4 or 8 pin connecter too.

Check the graphics card you buy, depending on how much grunt it has, it might need a 6 pin, two 6 pin, an 8 pin, a 6 pin and an 8 pin, or even two 8 pin PCIe connectors. The PCIe 8 pin connector can look similar but is NOT the same as the 8 pin ATX 12V conector.

Aside from that, go for an efficient PSU, the higher the better. Not only does this save electricity, it means it runs cooler, so it's worth spending a little bit extra for it.

Even for a low power system, the difference in electricity cost between an 80% and 85% efficient PSU can easily be $20 / year.

Hmm, this sounds pretty complicated with all these different types of connectors that I'd have to be sure of before buying anything.

How can I tell, beforehand, whether a prospective PSU will have the right kind and amount of connectors that the GPU will need? Can I trust that any PSU will have enough connectors for standard equipment AND a graphics card of the type that needs additional power connectors?

"Check the motherboard, it'll likely have a 24 pin ATX connector, and then optionally a 4 or 8 pin connecter too." This 4 or 8 pin connector -- what is it used for (what is it plugged into)?

Sorry for all these silly questions, but thanks for answering so far...

Rodrigo

[Rodrigo]

Originally Posted by LiquidNitrogen

As having built over 200 systems personally, I would like to impart a few words of wisdom regarding power supplies.

Something that is not on most people's radar when it comes to the Power Supply Unit (PSU) is the so-called "signal to noise" ratio. If you have a 300W PSU and you are up in the 260-280W range most of the time, you are getting close to the point where noise in the signal will become a factor for long-term computations. It's like inviting mini-brownouts a few times per 24 hours.

If, however, you are in the 260W-280W range and you have a 650W PSU, there is a snowball's chance in hell noise will be a factor.

A higher wattage PSU also gives you the flexibility to upgrade without too much concern. Add a couple more hard drives, throw in a better video card, add multiple Blu-ray burners, no problem. With a lower wattage PSU, you have to "count up" the watts every time you want to add something (because you never remember what the total was from the last time you did it!)

Thanks very much for the info. Yet another factor to throw into the witches' brew. *sigh*

Does it matter to the computer case or the motherboard, what wattage PSU one installs? (I mean, in terms of physically fitting.)

Rodrigo

[chalsall]

Originally Posted by Rodrigo

How can I tell, beforehand, whether a prospective PSU will have the right kind and amount of connectors that the GPU will need? Can I trust that any PSU will have enough connectors for standard equipment AND a graphics card of the type that needs additional power connectors?

Caveat emptor.

[Rodrigo]

Originally Posted by chalsall

Caveat emptor.

Thanks, this is valuable. It leads us back to the first question, which was whether it's possible to tell, BEFORE you buy, whether a given PSU comes with all the connectors you'll need.

Here's hoping that the best advice is more specific than, say, "Just buy the biggest, most expensive PSU that your wallet and PC can take."

Rodrigo