Question about voltage


Sorry if this post is a little too long but I really need to know whether my computer is running normal.

Since I first bought my computer about a year ago I've noticed that my +3.3V (this is AGP bus, right?) is slightly lower than 3.3, which is somewhere around 3.0V.

My computer spec:
Intel Pentium 4 2.6c Ghz
Asus P4P800 non-Deluxe motherboard (865 chipset)
Asus V9280 Geforce 4 TI 4200-8X 128MB
(Core: 243 Mhz, Memory: 513 Mhz)
2 * 256 MB DDR RAM
450 watt generic PSU

From Asus Probe 2 (monitoring utility for motherboard):
+12V -- 12.281
+5V -- 5.08
+3.3V -- 3.248
VCore -- 1.6

From Asus Smartdoctor 2 (monitoring utility for graphic card):
VDDQ -- 1.68 V
AGP Bus -- 3.00 V

(I'm no expert in this, but from my own guess, is AGP bus same as +3.3V? If so, the monitoring utility for graphic card shows the AGP bus has 3.00 V but in the utility for mobo, it shows the +3.3V has 3.2V. Which is more accurate?)

An interesting note is that when I first bought this computer, with a generic brand 450 watt PSU, all the games' graphics appeared to be corrupted or the entire monitor screen became black for a few seconds during games. After a few experiments I've done, I found out that removing one of the two RAM solved the problem. My own guess is that removing the RAM causes less power to be used, so the graphic card will have more adequate power to run the game. I also installed Asus Smartdoctor 2, a monitoring utility came along with my Asus TI 4200 box, and it shows the AGP bus has less than 3 V (even lower than the current 3.00 V). It is clear that the corrupted graphics are caused by inadequate power.

I went to the computer shop for repair, and they changed a new PSU for me (still generic 450 watt PSU but a little bit expensive than the old one) and it works now. The only problem is that the AGP bus still shows only 3.0 V, a little bit less than the desired 3.3 V. Is this normal for my computer?

Recently I planned to buy new RAMs (currently I plan for 2 more 256 MB RAM) for my computer. So, will installing additonal RAMs in my computer uses more power than before and cause my graphic card to have inadequate power supply again? If so, do I need a new PSU or are there any other ways to solve the problem?

Please advise.

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More about question voltage
  1. Are you sure it doesn't say AGP version: 3.0?

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  2. No it's not the AGP version. The AGP bus I mentioned vary from time to time, sometimes it's only 2.98 or 2.99 V and sometimes it's 3.02 V. If I increase the core speed and memory speed of the graphic card the AGP bus will be lower.
  3. Your voltages should be within 5% for spec. Your 3.3v rail is allowed to drop as low as 3.15v or jump up to 3.49v. I don't like anything lower than 3.2v or anything higher than 3.4v. Mine runs at 3.38v.

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  4. thanks for the reply. Any idea on how do I increase the voltage? Or do I have to buy a new PSU for it?

    <P ID="edit"><FONT SIZE=-1><EM>Edited by timothylondon on 10/09/04 02:42 AM.</EM></FONT></P>
  5. Unfortunately the readings from an Asus probe are consistantly wrong. I can't vouch for the version that comes with a pentium based mobo (though I suspect their abpout the same) but it is well known that you can't get an accurate reading from the probe. You might use the readings in the bios or google motherboard monitor. Either one will give you a more accurate reading of your voltage rails. Also, money spent on a good psu is well worth it.

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  6. I will guarantee the agp voltage reading is wrong. If your agp card were getting 3 volts, it would have fried a long time ago. It's normal v is 1.5. Asus doctor is ancient. It is from the agp 1X days. Forget it, and loose it. It is puc.
  7. thanks for the replies. I just downloaded Motherboard Monitor and the results are almost similar with the Probe:
    +12V -- 12.34 V
    +5V -- 5.08 V
    +3.3V -- 3.24 V
    Core -- 1.53 V

    Are the voltages normal? Also, will installing two more RAMs use more power than before? If so, how do I know if my power supply is enough to sustain two more RAMs?

    by the way is +3.3V the same as AGP Bus (as shown in Asus Smartdoctor 2) ?

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