Machine:
Mesh Matrix XP1800+ 512K DRAM PC2100 133MHz

Motherboard
ASUS A7N8X2.0 Rev 2.0
Chipset NVIDIA nforce2 Ultra400

BIOS
Phoenix Technologies
version ASUS A7N8X2.0 deluxe Rev. 1005

machine recently upgraded with
a. XP2600+ processor
b. 2.0GMB PC2700 333 MHz,
c. 2nd hard drive 80GB
d. NVIDIA GEFORCE4 Ti 4800 SE

Operating system Windows XP Home

Status:
Recently been having blue screen crashes
Found faults on two DDRAM units out of three, using the Microsoft Memory Diagnostic programme
The memory units were replaced (running OK so far)

The following voltages were obtained from Speedfan (Page…..Readings)

Question:
Do these voltages look OK?
Concerned about the +12v & -5v figures

CPU Core 1.62v
Aux 1.62v
+3.3v 3.28v
+5v 4.89v
+12v 11.67v
-12v 11.88v
-5v 4.62v


Regards
Roadrocket

According to the ATX Form Factor Standard, Section 4.1.4, Table 6, the voltage tolerances for the motherboard power rails are:

+5VDC ± 5 %
-5VDC (if used) ± 10 %
+12VDC ± 5 %
-12VDC ± 10 %
+3.3VDC ± 5 %
+5VSB ± 5 %

So it would appear yours are all fine.

Many Thanks Digerati

Youi have put my mind at rest

Cheers

No problem. But while at it, understand that current on the +12V rail is actually the money maker for PSUs as that is what drives power hungry graphics, among other things. Here's my canned text on using eXtreme's PSU Calculator to make sure you have enough oomph!

Use the eXtreme PSU Calculator Lite to determine your power supply unit (PSU) requirements. Plug in all the hardware you think you might have in 2 or 3 years (extra drives, bigger or 2nd video card, more RAM, etc.). Be sure to read and heed the notes at the bottom. I recommend you set Capacitor Aging to 30%, and if you participate in distributive computing projects (e.g. BOINC or Folding@Home), I recommend setting TDP to 100%. Research your video card and pay particular attention to the power supply requirements for your card listed on your video card maker's website. Then look for power supply brands listed under the "Good" column of PC Mechanic's PSU Reference List. Ensure the supplied amperage on the +12V rails of your chosen PSU meets the requirements of your video card. Don't try to save a few dollars by getting a cheap supply. Digital electronics, including CPUs, RAM, and today's advanced graphics cards, need clean, stable power. A good, well chosen supply will provide years of service and upgrade wiggle room. I strongly recommend you pick a supply with an efficiency rating equal to, or greater than 80%. Look for the 80 Plus - EnergyStar Compliant label. And don't forget to budget for a good UPS with AVR (automatic voltage regulation).

Spot on Digerati

I used the *eXtreme PSU Calculator Lite* and it reported I needed a 367 watt PSU currently, without any more additions.

My Mesh Computer has a 300 watt PSU

I installed a 400w supply (380w on the +12v , +5v & +3.3v rail)

The following changes were noted,

300w 400w
+12v 11.67 12.04 - 12.1
+5 4.89 4.76 - 4.78
3.3 3.28 3.36 - 3.34

I was surprised to see the 5v rail drop from 4.89 to 4.76, which is only 0.01v away from the -5%

When the 12v & the 3.3v increase to 12.1 & 3.36 respectively, the 5v rail drops from 4.78 to 4.76v

I would appreciate your views

I would appreciate your views

If it works, leave it alone. While the .01 is close, do not assume those readings are precisely accurate. It could be off either way by a small margin. Motherboard makers know this and so motherboards have regulator circuits too. But they can only do so much.

Also, not knowing anything of the brands or model numbers of either PSU, I cannot comment on them. But note I would much rather have a 500w Antec (or another brand from the "Good" list), than a 600w off-brand generic. More advertised watts does not equal better quality. But better quality generally results in a more stable computer system. If your PSU brand is not listed on the Good list, then I would consider replacing it. A good 650 - 750w PSU from a reputable maker can carry you through several years of hardware upgrades.

Also note that a power supply draws from the wall what it needs to support its load, and not what the PSU is rated. Power supplies are inherently inefficient. Most have a typical rating of only 70%, meaning for every 100 watts supplied, 30 watts are wasted in the form of heat. So, if everything powered by your power supply draws 282 watts, add 30% wasted to heat (about 85 watts), your electric bill will reflect 367 watts regardless if the power supply is a 400w PSU, or a 850w PSU.

So the differences come with quality. Better parts are made from purer materials to tighter tolerances. Note the best supplies have an 85% rating. You still waste 15% in the form of heat, but, that is less heat your facility air conditioning will have to remove too. More savings that can quickly pay for the higher prices of the better supplies.

I would expect the better makers to not use unsafe factories that emply(?) child slave labor too! With some supplies costing less than $10, it makes you wonder.

Another advantage is noise, or lack of it, especially important today when computers can easily have 7 or more fans whirling about, or are being used in a home theater where total silence is desired. Generally speaking, larger supplies have much larger heatsinks than smaller PSUs as they potentially have a lot more heat to move out. Better supplies (of all sizes) use speed controlled fans to help reduce noise when full power (maximum heat removal) is not needed. A 400watt supply working near capacity will be generating a lot of heat and will most likely call for the fan to run full speed. A larger supply, with its larger heatsinks, will have no problems dissipating heat away from the sensitive components, requiring only a soft (quiet) pull from the fan to draw the heat out the case.