Hi all. Long-time lurker and have finally created an account.

Looking for anyone's advice on PSU's for a retro system. I have a P3 450Mhz machine all built and working nicely. The PSU I built it with is an Antec HCG-400 unit, 80 plus bronze, which I bought new a couple of years ago. I thought using a newer PSU would be a good idea in terms of protecting the components from a faulty older supply. However whilst I was in the BIOS yesterday I had a look at the voltages in the PC health section, and found that many of them seemed high:

+3.3 = 3.48V
VTT(+1.5) = 1.7V
+5 = 5.26V
VCCVID(CPU) = 2.2V (should be 2.0V)
+12 = 13.67V (!)
-12 = -12.9V

Not entirely sure if this is much to be alarmed about and it seems OK stability wise. However, I had a dig through my parts box and found an older Qtec 500W PSU. Out of interest I swapped the PSUs, and the voltages now read almost dead on for each of them. The CPU in particular reads 1.99V which seems much better.

My dilemma comes from the fact that the Antec PSU is technically the better / more high quality unit, however the voltages seem off whilst using it. Now this might be because it'll be a newer revision of ATX - I'm obviously not using the "p4 connector", so perhaps it's not a very good fit for this board and CPU. Whilst the Qtec unit is older and probably a lower quality, it does seem fine in operation and the voltages seem right-on from the measurements in the BIOS. So what should I do? Continue using the Qtec unit I've put in there with the better voltages, or put the Antec unit which is technically higher quality back in, and just ignore the fact the voltages are off?

Some more info about the PSU's and system specs for reference:

- The newer Antec PSU is an HCG-400, 80-plus bronze, 20A on +5V, 30A on +12V, as you'd expect for a newer supply
- The older Qtec is a 500W unit (at least according to the sticker!) No 80-plus rating but it does feel fairly heavy, and is stable in operation. 35A on +5V, 18A on +12V

System specs:
P3 450Mhz slot 1
Legend QDI BrillianX motherboard, 440BX chipset
128MB SD-RAM
Geforce 256-DDR graphics card
Voodoo 2 12MB PCI
Intel 10/100 NIC
SB Live!
Adaptec 2940U2W PCI SCSI card
1 x Maxtor Atlas 36GB SCSI disk
1 x IBM Ultrastar 18GB Disk
1 x FDD
1 x SCSI CD-ROM

Thoughts & opinions most welcome!