Stability Testing

[Paratus]

My 12V rail has already been a little low, around 11.9v idle and dipping to 11.7v on load. Anyhow I re-ran two instances of PRIME 95 the other night and hit 11.5v which is starting to get me worried. (It did complete several hours of testing no issues).


What I want to do is use my digital multimeter to check the actual voltage under-load to verify what Asus PC Probe is telling me and I need some pointers on how to do that - safely.


My rig for those to lazy to click the link below is as follows:

Mobo - Asus P4P800 E deluxe
CPU - P4 3.2E skt 478 (Prescott :Q) at stock
RAM - 2x512mb Corsair PC 3200 XMS TCCD (2-2-2-5)
GPU - Asus 9600XT Vivo (Oc'd 526/648 from 500/600)
HDs - 1x 160GB WD SATA 8mb 7200RPM & 1 x 10GB WD PATA 5400RPM
OPT - 1xNEC 3500A DVD RW & 1x Samsung 16X DVD ROM
Fans - 4x 80mm case fans & Nexus Fan Bus
Misc - 1x Floppy & 1x 12in1 card reader

PSU - Coolmax Taurus 400W with 18A on the 12V rail


The PC has been running stabily for the last 1 1/2 years but I want a new GPU, larger HDs more Ram, etc and am worried that the PSU is not up to it.


Let me know what you think, I'm off to work so thanks in advance.

 

[Paratus]

bump

 

[lenjack]

The accepted allowed variation on the 12v line is 5%; This gives you an acceptable range of 11.4 to 12.6. Since you are in the allowed range I think you are fine.

 

[Shimmishim]

ok paratus this is how you do it.

you have the 4 pin molex that run from your psu that you use for hard drives, cd drives, mobo, etc.

there are 4 color wires that run to each molex... a red, a black, another black, and a yellow.

the two black ones are ground (no voltage) while the red one is for 5volt and the yellow is for 12 volt.

stick the black tip of your dmm into the black hole or outlet of the molex and the red end into the yellow.

measure with no load and this is your idle voltage. then load with 2 x prime and measure to get the drop due to load.

hope this helps.

 

[cmdrdredd]

If you have no problems with stability I wouldn't touch it.

 

[Paratus]

Thanks for the tips Shim! I'll give it a try this weekend.



posted via Palm Life Drive

 

[Paratus]

Good news! Asus PC Probe was reading low. My multimeter showed 11.99 idle (APCP 11.91) & 11.81 at load - 2 instances of P95 (APCP 11.58).

Thanks for the help. I feel a bit better about this PSU.


posted via Palm Life Drive

 

[lenjack]

Tpically, meters will read about .1 to .2 volts higher. Trust your meter.