First post, by kalm_traveler
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Hey guys, I searched around a little bit to see if we already had a thread of recommended modern power supplies for these old platforms but didn't come up with anything.
I understand that pre-Pentium 4 era, load was mainly on the +5v rail vs the shift to almost entirely on the +12v rail that we have now days which means that lower wattage modern PSUs are often not able to push enough amps on the +5v rail to properly run Pentium III and older systems.
That being said, I finally made up my mind on parts for my 98SE/2k rig and have it more or less buttoned up save for not having the final PSU sorted out. I'd purchased some old very high-watt PSUs to recap a couple years ago but didn't understand capacitor ratings properly so after replacing all the big caps on them they wouldn't turn on.
Currently, I have an old ~ 2004ish no-name PSU with 40A on the +5v rail that seems to boot and run this PIII rig but I don't trust it being so old, not recapped and a no-name brand. I also have a new EVGA 550w modular unit but it only has 20A on the +5v rail and with all PCI cards installed it won't turn the board on.
I watched a youtube video from I think Phil's Computer Lab some time ago where he mentioned this issue, and poking around I see that Corsair PSU's have a few more amps on their +5v rails when you step up into the really high watt supplies like the HX1200 has 30A on +5v but honestly 1000w and higher PSU's seem to all be snapped up by crypto miners these days so I'm not even sure I could find one of those if I wanted to justify the expense in the first place.
Are there any known new-ish other PSUs that should work for this?
For reference, this rig is built on:
an Asus TUSL2-C motherboard
PIII 1.13ghz Tualatin chip
3 sticks of PC-133 SDRAM (256mb, 128mb, 128mb)
AGP Quadro4 980XGL graphics card
Intel 1gbit NIC
USB 2.0 card
SATA card
Aureal Vortex 2 sound card
USB 3.0 card in PCI-E to PCI adapter (works under Win 2k, albeit not at full speed due to PCI bus limitations, still faster than USB 2.0)
IDE DVD-RW drive
floppy drive emulator
Ideally also have 4 case fans (12v fans) run by a Corsair fan controller.
All I can tell right now is if I remove some of the expansion cards, the 550w EVGA PSU will boot it up but with everything installed it seems to not have enough amps on that +5v rail as the machine won't turn on at all. With the old no-name PSU it boots up and seems to run more or less fine.
Any suggestions on modern PSUs I can look for, or are those expensive high-wattage Corsair units probably the only option?
Retro: Win2k/98SE - P3 1.13ghz, 512mb PC133 SDRAM, Quadro4 980XGL, Aureal Vortex 2
modern:i9 10980XE, 64gb DDR4, 2x Titan RTX | i9 9900KS, 32gb DDR4, RTX 2080 Ti | '19 Razer Blade Pro