AntiMoronic

Bought a comp about 18 month ago and from the start only a select few games would crash, and it would be a complete hard lock and have to reboot.

Just cracked open the case, and the psu I have:

-running a 9600gt, 3 fans, 500gb sata hd, dvd drive, and quad core is:

Allied Power Supply [AL-8500BTX] 500w

Under the voltage section I can see:

+3.3v - 22a
+5v - 6a
+12v1 - 15a

But then under current section, I see:

+12bv2 = 16a

Does that mean there are two rails, I can't see them?

Any way, thiis power supply clearly says for p4 - should it power a quad core AND a 9600gt and what I mentioned above?

I just bought this which has a single, 52a rail and well enough power apparently (in another thread):

http://www.scan.co.uk/Products/650W-...e-5yr-warranty

Thoughts? Will that be up to it?

Tumbleweed36

That power supply you purchased (the 650 Corsair) will certainly be up to the video card you have and even more. Nice selection.

That allied is not up to the job with what you have and you risk doing damage to other components if you use it, I would advise against it.

AntiMoronic

Can anybody explain what the 3.3v and 5v mean, what is plugged into my motherboard, cpu etc.?

I have no idea.

Can't take credit for the selection ;) One of the other saints suggested it.

Phædrus2401

The +3.3V is used for certain functions on the motherboard and some add-on cards, as well as low-speed fans. The +5V is used for the hard drive motors, some motherboard and add-on card functions, and moderate-speed fans. The +12V is used for most motherboard power, the CPU, RAM, graphics card, HDD PCB power, high-speed fans, and most everything else.

A sign of a good power supply is that the +12V power (calculated by multiplying 12 x the current available on the +12V rail(s)) makes up at least 80% of the PSU's total wattage. Most Corsair PSUs have the +12V make up ~90% of the power rating.

AnteRep

Allow me to add one more point here.

An advanced power supply should provide robust and reliable circuit protection technologies. However, a lot of popular brands are offering high power supplies without Over Current Protection (OCP). One brand recently came out with a model that has a +12 Volt rail supporting nearly 80 Amps without OCP! Ironically, they include OCP on the lower amperage rails (3.3V and 5V) but leave it out on the most important rail. Using a power supply without robust OCP, the motherboard will extract as much current as it can when there is a short circuit within it until it burns the system.

It is very important to build a high performance system using a PSU with OCP on ALL rails.

Phædrus2401

Good contribution! Yes, we try to only recommend power supplies with good protections. We consider over voltage protection (OVP), over current protection (OCP) and short circuit protection (SCP) to be 100% vital, and strongly recommend purchasing a power supply with under voltage, over power, and over temperature protections (UVP, OPP, OTP), though we won't condemn an otherwise decent PSU just because it lacks these.


We also take other things into account when recommending power supplies, including efficiency (as tested at 40-50C), noise/ripple levels, voltage regulation, temperature tested at (we prefer to see PSUs rated at 40-50C), quality of internal components such as the capacitors (Japanese rated at 85C+ are preferred), and the +12V rail layout (on a single rail design this isn't an issue, but on a multi-rail design we like to see an even distribution of load across all rails).