You can't go wrong with the Seasonic S12, M12 series. The M is the modular. I usually avoid modular as you need to keep track of the cables 😀

lrochfort wrote:

Hi all, […]
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Hi all,

I have a slot 1 PIII system with two 10k scsi drives, cdrom, floppy, a Geforce 4 AGP card, and 2-3 fans.

I think my existing PSU is failing to supply enough current for the SCSI drives when they spin up and generally has issues.

Could you recommend a modular-cable PSU for this system load?

I think I need 3 molex, one floppy, and one ATX connector.

Cheers!

PIII still relies heavy on 5V rail which are poorly supported on new PSU vwith low wattages, your best option would be recapping a good quality one. I have no idea what your power requirements, but my pIII runs great on a antec 450W with 30A ish on 5V

Richo wrote:

lrochfort wrote:

I think I need 3 molex, one floppy, and one ATX connector.

Cheers!

PIII still relies heavy on 5V rail which are poorly supported on new PSU vwith low wattages, your best option would be recapping a good quality one. I have no idea what your power requirements, but my pIII runs great on a antec 450W with 30A ish on 5V

If you're aiming for an older PSU just in case this is a problem, I'd personally go for good-quality OEM PSUs pulled from older units. I'm using a Dell 200W PSU from an old grey Optiplex to power my Slot 1 build and it's working perfectly.

A general rule of thumb for Dell power supplies is that only those from a specific era will work with your build (assuming you'll use a standard ATX board), avoid supplies pulled from the beige systems (GX110 or earlier) because those use a proprietary pinout which can be noticed by the supply having an extra AT-like connector in addition to 20-pin ATX, A supply from a grey Dell (GX150, GX240 or newer) is what you'll want because Dell switched to standard ATX for that generation (just look for one with a P4 connector).

As with any older power supply, I encourage checking the caps and blowing the dust out of it when you have the chance.

You should have just enough connectors to satisfy your requirements in that area, I can confirm those Dell tower PSUs have at least 4 molex connectors in addition to the floppy and ATX connectors.

I would suggest Hi-Pro 200-300 watt units from P4 era systems. Most of the ones I have pulled have a million hours on them and still hold up great, mostly with good caps. Bestec is also a less safe bet, they have some BAD 250 watt units from that era but the 300's iv pulled have all been pretty solid, despite the bulged cap or two. They liked to use some pretty bleh tier caps. The Jamicon and Teapo filled 300watt units seem to be pretty decent but the 250's are full of CRAPXON's and have an unsafe 5v rail.

Thanks all. Unfoetunately the only older and OEM units I have are newer Dell and Lenovo units which have all kind of proprietary craziness on them!

I ordered an S12 which had reasonable 5V amperage, so we'll see how it goes.

Personally I have had good luck with Logisys supplies, however, I have heard bad things about them as well. They do claim some well important specs.

Because I love Corsair, and it would be amusing, for my future Pentium Pro build, I plan to use this supply:

https://www.newegg.com/Product/Product.aspx?I … N82E16817139198

Most supplies rebranded by EVGA, made by Corsair, or Seasonic are pretty good. Cooler Master, while not my favourite, is also not bad for the supplies they make.

elod wrote:

You can't go wrong with the Seasonic S12, M12 series. The M is the modular. I usually avoid modular as you need to keep track of the cables 😀

Unless you want to clean and recap an ATX 1.0 era power supply, I vote the S12II 520 if you aren't just looking for something junkyard priced and want a new unit. Have to check if the 20+4 is separable though, since it may cause clearance issues with some boards. You can get them in the US on newegg for 44.99, 29.99 after rebate. They are incredibly reliable. 24A on +5v is more than plenty for a Pentium 3 supposing you aren't going nuts on drives and 5v molex powered devices., slot 1 coppermine 1000mhz has a TDP of around 30 watts. If you want to turn around and swap it into a modern PC then you get all that 12v glory.. For the price it's just worth it to me.

The supply that came with my pentium 4 HT 2.8Ghz system does +5V@21A, for comparison since people mention p4 era supplies.

http://www.jonnyguru.com/modules.php?name=NDR … =Story&reid=185 -- review of S12II

Most fans are 12 volt, and *I believe, not positive* that mechanical power for your hard disk drives is also from the 12v line, molex has pins for both 5v and 12v. Also IIRC legacy AGP cards draw 3.3v and later cards like a radeon 9800 pull from 12v. Don't quote me on any of this and do your research if need be, it's been a long time, but I don't think we need to shoot for excessive 5v amperage.

I can't possibly see the machine needing over 24A, but I could be wrong with some crazy setup.

Ampera wrote:

https://www.newegg.com/Product/Product.aspx?I … N82E16817139198

This Corsair is not 2010's Corsair. EVGA as well I think.
I'd stick with the OEMs that really make PSUs: Seasonic, FSP, maybe Superflower? Or really research what components the specific PSU uses and who the OEM is.

elod wrote:

Ampera wrote:

https://www.newegg.com/Product/Product.aspx?I … N82E16817139198

This Corsair is not 2010's Corsair. EVGA as well I think.
I'd stick with the OEMs that really make PSUs: Seasonic, FSP, maybe Superflower? Or really research what components the specific PSU uses and who the OEM is.

Eh, on second thought, I might risk it and grab a Logisys supply. I know they have an iffy track record, but I have had 2-3 of these supplies working and working well for years.