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Davesdad
28-02-2005, 09:35 PM
Today my PC has started displaying an error from the Graphic card that it is receiving insufficient power and is reducing performance to protect the GPU. The Windows event log has this error message "Silent running: HW clock slowdown due to missing Auxiliary power." The Graphic card is a Gainward nVidia GeForce FX 5900 and the power supply is a Thermaltake W0008RAC, Silent Purepower 420W. MBM5 is showing the voltages as follows:
Core 0 1.67v
Core 1 2.56v
+3.3v 3.38v
+5.00v 4.08v
+12.00v 11.49v

The rest of the scec are: Gigabyte GA-7N400 pro 2, Athlon XP 2800+ Barton, Thermaltake Volcano 12 CPU cooler, Thermaltake Smart fan II case fan, 1x Seagate 80GB ATA, 2x Seagate 80GB SATA(added about a month ago), DVD-ROM, DVD-RW DL(upgraded from CD-RW about a month ago).

The more I look at this the more I think I may be overtaxing the power supply. The +5.00v is looking particularly dodgy. The Graphic card, ATA drive and FDD are powered from the same rail.

I would like to here some thoughts on this. Tomorrow I will unplug a few drives and see if it makes a difference to the voltages

Davesdad

godfather
28-02-2005, 09:45 PM
There should be a cable that connects it to a standard 4 pin molex connector (HDD type power cable) for auxiliary power.

It's complaining that it is not connected?

Davesdad
28-02-2005, 09:56 PM
There should be a cable that connects it to a standard 4 pin molex connector (HDD type power cable) for auxiliary power.

It's complaining that it is not connected?
It is connected

PaulD
28-02-2005, 11:15 PM
The +12V rail is the one supplying the CPU, most of the video card and the drive motors, so that is the one most likely to be struggling.

george12
28-02-2005, 11:22 PM
12v and 5v are really struggling there. 12v should not be below 12v, and 5v should not be lower than about 4.7v under any circumstances. I'm surprised you're not getting random lockups.

It's a good power supply though, I am quite surprised that it isn't doing too well with that load. Try removing a few drives and see what happens.

Wombat
28-02-2005, 11:45 PM
It's a good power supply though, I am quite surprised that it isn't doing too well with that load.
I'm not surprised at all. Those Thermaltakes have pathetically low rails and it doesn't take much to overload them. I bet an Enermax 420W would still be running fine, in fact I've run more high power components off an Enermax 350W!

As has been said, try removing all the stuff you don't absolutely need. Power up with the minimum graphics card, hard drive and see if you still get the error.

If you don't then time to buy a more reliable PSU like an Enermax 470W which has two times better specs.

KatiMike
01-03-2005, 01:31 AM
that's a great reply Wombat , kind of why I hang around "lurking "

I hope you stick around and advise when appropriate , and share your experience

Mike W

Davesdad
01-03-2005, 10:23 AM
Update time

I disconnected the SATA and optical drives and booted to my old XP installation on the ATA drive. MBM5 showed the voltages as:

Core 0 1.71 up from 1.67
Core 1 2.58 up from 2.56
+3.3 3.39 up from 3.38
+5.00 4.31 up from 4.08
+12.00 11.9 up from 11.49

I then reconnected all the drives and booted from the ATA drive. The voltages were exactly the same as when the drives were disconnected so it looks like MBM5 configuration is responsible for the different readings. I looked in the BIOS at the voltages but it doesn't display the actual voltage it just says OK for all.
I even played a little Far Cry last night without any problems although I was getting fatal exceptions when I first setup the SATA drives.

I will try removing all non essential hardware tonight and see if it makes any difference to the voltages and post back tomorrow with the results

Davesdad

Billy T
01-03-2005, 11:27 AM
Motherboard monitors are notoriously unreliable when measuring PSU voltages. You are better to go buy a cheap digital meter from DSE or Jaycar, even the cheapest will give far more accurate results.

I'd want to know the true voltages before I did anything drastic. Cat. Q1467 costs just $12 and even has a data hold function.

Cheers

Billy 8-{)

wintertide
01-03-2005, 12:18 PM
PSU voltage rails are meant to have a 10% tolerance in them either way so if it's below 10% of the tolerance on any of the rails then you're overloading the PSU.

Davesdad
02-03-2005, 11:42 AM
Motherboard monitors are notoriously unreliable when measuring PSU voltages. You are better to go buy a cheap digital meter from DSE or Jaycar, even the cheapest will give far more accurate results.

I'd want to know the true voltages before I did anything drastic. Cat. Q1467 costs just $12 and even has a data hold function.

Cheers

Billy 8-{)
Thanks Billy

I back probed the power connectors and the voltages are ok

Molex connector to video card
+5v = 5.16
+12v = 12.0
GND = 0.0002v

Main ATX Power
+3.3v = all 3.42v
+5v = all 5.16
-5v = -5.11v
+12v = +12.02
-12v = -11.77v
GND = -0.0035v to -0.004.7v

The original problem has not occured again so hopefully it was just an isolated incident. :)

Graham L
02-03-2005, 03:35 PM
Yet again, an illustration of how misleading uncalibrated sensors can be. "4.08" looks serious for a 5V supply. "It must be right, the computer says so" (to two decimal places) . :groan: