How do you test a power supply

[smilingfrog]

Hi all,
I recently built a new system, which has been up and running for six months, but not without issues.

I have an Antec EA-650 EarthWatts 650W Continuous Power Supply powering an ASUS P7P55D Pro mobo with an Intel i5-750 processor.

There are 8GB of CORSAIR XMS3 DHX 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333, which had been running at just under 1.6V according to the BIOS.

I have been running Ubuntu Linux 10.04 pretty much since the build, and have blammed the freezes and crashes on the 64 bit OS.

Secondary to a post on ubuntu forums, it has been suggested that my power supply may be the issue. It's possible, but my gut tells me it is not. I would like some help in figuring out how to test the power supply without having to send it back. I pretty much have to buy a new power supply to keep the machine running in order to test the original PSU, right?

As an aside, I did a bit of online research on the RAM, and some people have suggested that the voltage is listed incorrectly for this RAM. I dialed it up to 1.7V, and so far the computer is much more stable. Any comments on the RAM would also be appreciated.

G

[Nikon]

i dont think it is the PSU, but it is possible i suppose...

find the exact model number for your ram, and go find out what settings it should be at. ram operating over 1.5v is usually a sign of a problem.

i would suggest a good long run of memtest first. others here know more about this than i do, so i will not go into depth so as to avoid misdirecting you.

[David M]

If you still can, I would return the RAM you have and replace it with 1.5 volt, 1333 RAM. It could very well be that the RAM you have is causing the instability issue. Your board natively runs 1600 RAM so that would be okay as well. Your board has a MemOK feature...all you have to do is press the button on the motherboard and it will do a test and adjust your RAM to "failsafe" settings. That's the problem with RAM with the higher voltages, higher BUS speeds and tighter timings...it is less likely to be stable. Overclockers love it but the reality is that this kind of RAM only adds a few percentage points in overall speed to your computer.

MemOK!
Any Memory is A-OK!
MemOK! quickly ensures memory boot compatibility. This remarkable memory rescue tool requires a mere push of a button to patch memory issues. MemOK! determines failsafe settings and dramatically improves your system boot success. Get your system up and running in no time!
ASUSTeK Computer Inc.

So you can rule out the PSU as a possibility, the bottom line test for a PSU is to test the three different voltages that it produces with a multimeter. Do this while your computer is under a load. The differences should not be over 10%. 7% or less is decent.

[smilingfrog]

Thanks for the advice. I called tech support at corsair, and they promptly agreed to an RMA. I went to the site to register for the RMA and a troubleshooting page came up with this:

The problem you're experiencing may be from a motherboard limitation. 
Most motherboards may be able to run four modules at a time, but not at high speeds.
You may have to slow your memory down and/or increase your northbridge voltage 
slightly to get all four modules running. If you’re not comfortable making these adjustments,
 or if the BIOS doesn’t allow for these adjustments to be made, you might want 
to consider one of our 4GB memory kits.

I have 4x2GB modules of memory. The frequency is set to 1333MHz in the Bios, and the RAM voltage has been turned up to 1.7V. Things now appear to be quite stable. Is this what they are referring to with regards to the northbridge? Should I still go ahead with the RMA?

[glc]

Any PSU voltage more than 5% off from spec is not good.

You will probably have to overvolt that ram to keep it stable. I don't like filling all 4 slots on general principles. Ask Corsair what the maximum safe voltage is for that particular ram.