Author Topic: Power reading from PSU, skuzzy or anyone (Read 300 times)

whels · « **on:** February 09, 2005, 02:14:01 PM »

what are the ranges should the +3 +5 and +12 be in?

whels

Skuzzy · « **Reply #1 on:** February 09, 2005, 04:19:42 PM »

Ranges?

The 3V rail better not be fluctuating at all, but it probably will be ok at 2.95V.
The 5V rail can be happy in the 4.8 to 5.2 arena, and the 12V rail should be okay in the 11.5 to 12.5 area.

If the 3V rail is bouncing around, you can expect some instability in the system. There is not a lot of room for this rail to move around.

What is it doing?
I told you that 430W supply is not going to be enough for that SLI system of yours. You did replace/upgrade it, right?

eagl · « **Reply #2 on:** February 09, 2005, 05:34:11 PM »

I thought it was supposed to be a 3.3v rail, not 3v. 2.95 would be pretty darn low for a 3.3v line... That's around 10% low.

I've read that the mobo sensors can't be trusted completely, and your best bet at getting accurate voltage readings is to take them directly from either a psu lead or from certain traces on the motherboard using a quality voltmeter.

I think some high end enthusiast power supplies even have built in voltage sensors and readouts so you can individually tune each voltage rail, but that's way too geeky for me. I know some memory modules now have LED displays attached to them that will read out temperatures, latency settings, and voltage, but that's pretty expensive. Some overclockers will find the right traces and components on their motherboards and solder on leads that they attach to a voltmeter and patch panel so they can monitor actual voltage to various components as they mess with their systems.

Again, that's too geeky for most people, so I think most people end up just buying a huge PSU and being done with it. PC Power and Cooling has a good rep and I think they sell a 550 watt or 600 watt PSU that should be bulletproof.

whels · « **Reply #3 on:** February 09, 2005, 05:40:51 PM »

Quote

Originally posted by Skuzzy
Ranges?

The 3V rail better not be fluctuating at all, but it probably will be ok at 2.95V.
The 5V rail can be happy in the 4.8 to 5.2 arena, and the 12V rail should be okay in the 11.5 to 12.5 area.

If the 3V rail is bouncing around, you can expect some instability in the system. There is not a lot of room for this rail to move around.

What is it doing?
I told you that 430W supply is not going to be enough for that SLI system of yours. You did replace/upgrade it, right?

3v is bouncing from 3.31 to 3.3
5v stays at 5.02
12v bounces from 11.53 low to 11.66 high

i havent replaced PSU yet, plan on getting a 680W this 1
http://www.newegg.com/app/viewProductDesc.asp?description=17-153-021&depa=1

whels · « **Reply #4 on:** February 09, 2005, 05:43:55 PM »

Quote

Originally posted by eagl
I thought it was supposed to be a 3.3v rail, not 3v. 2.95 would be pretty darn low for a 3.3v line... That's around 10% low.

I've read that the mobo sensors can't be trusted completely, and your best bet at getting accurate voltage readings is to take them directly from either a psu lead or from certain traces on the motherboard using a quality voltmeter.

I think some high end enthusiast power supplies even have built in voltage sensors and readouts so you can individually tune each voltage rail, but that's way too geeky for me. I know some memory modules now have LED displays attached to them that will read out temperatures, latency settings, and voltage, but that's pretty expensive. Some overclockers will find the right traces and components on their motherboards and solder on leads that they attach to a voltmeter and patch panel so they can monitor actual voltage to various components as they mess with their systems.

Again, that's too geeky for most people, so I think most people end up just buying a huge PSU and being done with it. PC Power and Cooling has a good rep and I think they sell a 550 watt or 600 watt PSU that should be bulletproof.

yes its the 3.3v he is talking about. i use Motherboard Monitor just
to keep tabs on temps and things.

whels

eagl · « **Reply #5 on:** February 09, 2005, 05:46:38 PM »

The 3.3v rail sounds fine, but the 12v rail sounds low. According to some reviews I read, the 12v rail on older power supplies is really stressed by newer motherboards regardless of the wattage rating. You gotta look at the specs for each rail to see how many amps it can support to each voltage. 11.53 is pretty low for 12v I think.

For an interim solution, you could try attaching all of your case and cpu fans directly to the power supply molex connectors using adaptors. You'll lose the ability to monitor the fan speed but it won't be drawing as much power over the mobo connector. I've heard of that working on older mobos (like 4 years ago) but I don't know if that trick will still do any good. I guess it probably wouldn't hurt to try if you have any of those molex to 3-pin fan adaptors around.

Skuzzy · « **Reply #6 on:** February 09, 2005, 05:47:39 PM »

Yes it is 3.3V. I thought it was safe to assume. 2.95 is the lowest you can go, generally speaking and only for short periods of time.

And eagl is right. Do not trust motherboard BIOS readouts for those readings. They are usually wrong.

That 12V rail looks suspect.