psu ok?

vishal · 12-09-2004 1:53pm #1

i upgraded by old 300watt psu a month and a half ago to a thermaltake butterfly psu 480 watt for a new gpu. the values in mbm5 are attached

why are the -12 and -5v rails so variable?

BloodBath · 12-09-2004 3:52pm

You should be happy. Getting slightly higher voltages is a good thing especially for overclocking. The 12v rail is the most important as it powers the mobo and cpu.

My thermaltake butterfly under volts to 11.6 when I overclock to 3.6. Any higher and the psu craps out and shuts down. If it was as high as yours i'd be able to get 3.8-4.0ghz out of the processor.

BloodBath

vishal · 12-09-2004 3:59pm

what about the -12 and -5. they are all over the place!

also what yours at stock speeds?

Col_Loki · 12-09-2004 4:11pm

The - voltage rails are to be ignored there not important TBH. The 12v Rail is a little high, i wouldnt call it a good thing but its within tollerance level......

vishal · 12-09-2004 6:06pm

if i were to overclock, would the the 12v line decrease in voltages?

Col_Loki · 12-09-2004 6:28pm

Quite possibly yea, it should decrease.....

Inspector Gadget · 12-09-2004 6:38pm

The supplied voltage on each line will drop as current demand increases once the overall power (voltage X current) exceeds what the PSU can deliver on that line. In other words, it will eventually, but only when you get close to the PSUs rating for that line.

12.6v is the upper limit for what a 12v line should deliver. (12v +/- 5%). The voltage sensing on the board may also be out a little. This is usually more noticeable with temperature sensors, but it does happen...

Hope this helps,
Gadget

vishal · 12-09-2004 6:57pm

i let mbm5 run on all day today and on the +12v line it dropped 0.36 volt at one stage? if this was the case wouldn't the pc lock up?

Inspector Gadget · 13-09-2004 9:45am

The tolerance I quoted earlier (+/- 5%) is taken directly from the ATX specs - in other words, for a motherboard to be powered by an ATX-type supply, it has to be able to account for a deviation of this amount on the +12v (as well as the +3.3 and the +5 - I think the negative rails have a 10-20% tolerance, don't remember offhand)

In other words, the "correct" range for the +12v rail is 11.4 (95% of 12) to 12.6 (105% of 12) volts - try not to worry so much; if there's a problem, you're likely to know about it long before you read it in your MBM logs. (That voltage drop could be anything , even just an optical drive spinning up; you'll get occasional glitches as the load level changes - the PSU takes a while to correct itself). Once the temperatures are relatively stable you should be grand.

Hope this helps,
Gadget

psu ok?

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