The 30A on the 5V line is the needle in the eBaystack. I can find quite a few units with 20A on the 5V but nothing higher than that. I’ll keep an eye out for that combination of specs...

pixelatedscraps wrote on 2021-03-21, 14:38:

The 30A on the 5V line is the needle in the eBaystack. I can find quite a few units with 20A on the 5V but nothing higher than that. I’ll keep an eye out for that combination of specs...

My choice for my main Pentium 3 setup is a Corsair RM850x . It has 25A on the 5V rail, 25A on the 3.3V rail and a max load of 150W for those rails combined.
I don't think you would need 30A on the 5V rail for a Pentium 3 build, unless it's a dual CPU setup with an exceptional amount of add-in cards . I was worried too, initially, but everything has worked fine so far .

Here are my observations from this thread Any modern psu's that have large 5v rails that I have re-posted here and abridged for clarity .

darry wrote on 2020-05-20, 14:07:

I currently have the following power-consuming parts: […]
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I currently have the following power-consuming parts:

- Pentium 3 Tualatin-S @1400MHz with 512K L2 cache
- Ipox 3ETI23 industrial motherboard (815EP-based with 3 ISA slots and onboard Fast Ethernet)
- 512 MB (2x256) of PC133 SDRAM
- MSI AGP Nvidia FX 5900
- 3Dfx Voodoo 3 3000 (PCI)
- 500GB Samsung 860EVO + JMD330 IDE to SATA adapter or Promise PCI SATA controller (have yet to decide) .
- 5 and 1/4" floppy drive
- 3 and 1/2" floppy drive
- LG GSA-4167 DVD-ROM drive
- Gravis Ultrasound Ultralsound 3.73 with 1 MB RAM
- Creative AWE64 Value with 28MB RAM (thanks to SIMMCONN revival)
- Mediatrix Audiotrix 3DXG (OPL3SA) with Monster Sound (Dream 9733 4MB GS ROM) daughterboard
- 3 case fans (12V ones so not worried about those) .
- USB keyboard
- PS/2 mouse

darry wrote on 2020-05-20, 16:59:

Oh, and I realized I have a Kill-a-watt type power meter . I ran Prime95 , then I ran 3DMARK 2001 at 1600x1200 . […]
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Oh, and I realized I have a Kill-a-watt type power meter .
I ran Prime95 , then I ran 3DMARK 2001 at 1600x1200 .

The highest load was when running 3DMARK 2001: at wall socket I got 160W using an old Enermax EG465P-VE (35A each on 3.3 and 5V and 200W combined). Assuming an 80% 70% (optimistic) efficiency rating, I should be OK with the PSU providing about 128W 112W or less . I should be OK with the RM850x, except if I have the same issue as you do with the TX-650W ( I don't feel like throwing in more drives) .

EDIT : My EG465P-VE variant (there are at least 3) has 70% efficiency at full load according to an old Bjorn3d review . https://bjorn3d.com/2003/07/enermax-eg465p-ve … c-power-supply/

darry wrote on 2020-05-24, 05:55:

I installed my RM850x today and gave it spin in 3DMARK 2001 at 1600x1200 . It peaked at 146 Watts at the outlet with an average of about 130 Watts , all under load. When idle in DOS, I get about 90 Watts at the outlet . So, considering that represents less than 20% load, efficiency should be somewhere between 87 % and 90 % . That means peak power draw was, at most, about 131 Watts with an average of about 117 Watts under load .

Almost all of that is on 3.3V and 5V rails (main 12V user is probably my FX 5900 , other 12V "users" include 2 floppy drives and a DVD-ROM drive along with 3 case fans ) .

I feel I am cutting it a bit close, but I guess over-current protection will kick-in if ever things get too intense .

RM850x manual --> https://www.corsair.com/corsairmedia/sys_mast … 2018_Manual.pdf

darry wrote on 2021-03-21, 15:25:

I don't think you would need 30A on the 5V rail for a Pentium 3 build, unless it's a dual CPU setup with an exceptional amount of add-in cards .

My Dual P-!!! takes a maximum of 18 amps so 25 amps is more than enough even for a Dual P-!!! system.

The PSU is a https://uk.thermaltake.com/smart-dps-g-650w-gold.html

I just managed to score a cleaned and tested FSP300-60 PLN with 180W on the 3.3V and 5V rails, and 30A just in the 5V. It wasn’t cheap at $40 and my fingers are crossed it arrives in good, working and clean condition.