Look at the 1-star reviews. A couple say that PSU fried components... I wouldn't touch that model with a 10-foot pole.

What are the specs of the rest of the computer you are needing a PSU for?

This EVGA 500W seems liek ti would be fine:
https://www.amazon.com/EVGA-100-BR-0500-K1-Br … y/dp/B07DTMXD83

cyclone3d wrote on 2020-09-18, 00:42:

Look at the 1-star reviews. A couple say that PSU fried components... I wouldn't touch that model with a 10-foot pole. […]
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Look at the 1-star reviews. A couple say that PSU fried components... I wouldn't touch that model with a 10-foot pole.

What are the specs of the rest of the computer you are needing a PSU for?

This EVGA 500W seems liek ti would be fine:
https://www.amazon.com/EVGA-100-BR-0500-K1-Br … y/dp/B07DTMXD83

I second that this EVGA would be fine for a non-overkill (up to a single relatively high end PCIEX video card) on a Pentium 4 or newer build (12V heavy). It will likely suffice for Pentium 3 or lower without too many cards. I don't recommend running a high end socket A Athlon (5V heavy) CPU on that, though, as some of them draw up to 79W on the 5V rail (on most motherboards) just for the CPU, which does not leave much for a video card and the rest of the system! That EVGA PSU only does 120W combined on 3.3V and 5V rails .

I’d probably use it in a Slot1 p3 system dual Voodoo 2’s.

How about this one instead?

EVGA 100-W1-0500-KR 500 W1, 80+ White 500W, 3 Year Warranty, Power Supply, Black https://www.amazon.com/dp/B00H33SFJU/ref=cm_s … i_dkbzFbT280GGX

I’d actually prefer a semi-modular PSU to clean up some of the cabling.

Maybe this one for a semi-modular?

EVGA 110-BQ-0500-K1, 500 Bq, 80+ Bronze 500W, Semi Modular, FDB Fan, 3 Year Warranty, Power Supply https://www.amazon.com/dp/B01N3OAFHD/ref=cm_s … i_cubzFbKT40NVJ

The EVGA 110-BQ-0500-K1 has only 110W combined on 5V + 3.3V rails, so I would skip that . The 100-W1-0500-KR has 120W combined,

Each Voodoo 2 is PCI and draws 15W on 5V rail , so a total of 30W for those.
A Pentium 3, depending on model, can draw up to 34.5W.
Add about 10-15W for a low end AGP video card or say 35W for a higher end like a Geforce 4 (how much of that is 5V v aries)
Each ISA card will draw a few watts from the 5V rail as well .

In other words, it may be a bit of a tight fit even for a P3 .

darry wrote on 2020-09-18, 02:26:

The EVGA 110-BQ-0500-K1 has only 110W combined on 5V + 3.3V rails, so I would skip that . The 100-W1-0500-KR has 120W combined,

In other words, it may be a bit of a tight fit even for a P3 .

Agree ! EVGA does have some very good PSU but with older P2/p3/Athlon stuff you need bigger 3.3+5v combined. Be patient and look around and see if you can find one with 130w+ but most those will not have -5v so some old ISA stuff may not work proper....
If just looking to power a AT like 486, Pentium or P.Pro then most good ATX will work (with AT adapter) if it can deliver 20Amp on the 5v (or 100w combined but you are not using the 3.3, be sure to check the label on the 5v max amps) but again you may not get -5v... just some thoughts

Edit: just looked at the EVGA 600 Ba, 80 Plus Bronze 600w, Power Supply 100-Ba-0600-K1 at Amazon and it does say 120w combined and 20A on 5v:
https://www.amazon.com/EVGA-Bronze-Power-Supp … /dp/B08BNRGWXZ/
Also: EVGA 100-BR-0500-K1 500 BR, 80+ Bronze 500W has 120w combined and 20A on 5v:
https://www.amazon.com/EVGA-100-BR-0500-K1-Br … y/dp/B07DTMXD83
either one should work well for older AT boards IMHO...minus the -5v

Wasn't there a guide around here on how to mod a basic AT-ATX to create the missing -5v? I seem to remember reading something like that.

Someone on eBay was selling a bunch of pre -5v modded adapters a wee bit back. But they seem to have dissapeared.

In reality and from my experience, every modern PSU will work gladly with retro hardware. Only problem is that -5, but it is needed only with very retro hardware. If you do not mess around with XT stuff or own a LAPC-I , then really you are not missing mutch.

There are ATX to AT converter cables which also have the needed -5v pin included. I bought 2 of them last year on ebay for my retro builds and they work like a charm. I just contacted the dealer to see whether he has any in stock and will be relisting them again. Will keep you updated.

skel2raw wrote on 2020-09-18, 08:57:

There are ATX to AT converter cables which also have the needed -5v pin included. I bought 2 of them last year on ebay for my retro builds and they work like a charm. I just contacted the dealer to see whether he has any in stock and will be relisting them again. Will keep you updated.

Please, PLEASE let us know. That would be an absolute god send. Regular At-ATX adapters just don't cut it for the price.

Unfortunately I didn't get a response so far from the dealer... but I found another thread here where the same covnerter is shown and some describes how you could mod a converter with the -5v. It's the third picture in the first post ATX to AT adapters, which one do I need and why?

There's always this option as well.. however from the reviews it looks hit or miss.

https://www.amazon.com/Athena-Power-AP-AT30-S … r/dp/B0042P2IIG

I think the worries about the 5V line are overrated. Take a look at how much power a retro system draws from the wall.

As an example, I tested an old Dell from 2001, having P4 1.6 Willamette + 1GB Rambus mem + GF3 + SB Live + HDD, and the whole system drew about 131 watts from the outlet, under load. If you multiply that by a very optimistic 80% PSU efficiency, that's about 105W total system consumption on the DC output side.

Now if you replace that with a P3 and SDRAM, then you can subtract another 20-30 watts from that figure. So unless you plan on running a top of the line Athlon Thunderbird, then 120W combined 5V + 3.3V output should be fine.

Another aspect of power supplies to consider is how the output is regulated. More expensive units have a DC converter that derives 5V and 3.3V outputs from the 12V line. These units are less affected by crossloads that place a disproportionately high load on the 3.3v or 5v lines.

Cheaper units are group regulated, where having too much load on 3.3v or 5v lines would cause the voltage on the 12v line to go higher than normal.

pixel_workbench wrote on 2020-09-23, 07:42:

I think the worries about the 5V line are overrated. Take a look at how much power a retro system draws from the wall. […]
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I think the worries about the 5V line are overrated. Take a look at how much power a retro system draws from the wall.

As an example, I tested an old Dell from 2001, having P4 1.6 Willamette + 1GB Rambus mem + GF3 + SB Live + HDD, and the whole system drew about 131 watts from the outlet, under load. If you multiply that by a very optimistic 80% PSU efficiency, that's about 105W total system consumption on the DC output side.

Now if you replace that with a P3 and SDRAM, then you can subtract another 20-30 watts from that figure. So unless you plan on running a top of the line Athlon Thunderbird, then 120W combined 5V + 3.3V output should be fine.

Another aspect of power supplies to consider is how the output is regulated. More expensive units have a DC converter that derives 5V and 3.3V outputs from the 12V line. These units are less affected by crossloads that place a disproportionately high load on the 3.3v or 5v lines.

Cheaper units are group regulated, where having too much load on 3.3v or 5v lines would cause the voltage on the 12v line to go higher than normal.

Most of that 105W in your build will be on 3.3 and 5V rails (pretty much only HDD, fans,CDs, floppies and maybe VGA card to a point will use 12V) . Add a disk controller card, an extra sound card or 2 and a NIC, all 3.3V/ 5V devices, and you are getting awefully close to a typical 110W/120W 3.3v/5v limits on inexpensive PSUs .

My Pentium 3 based system, under load, draws about 117W to 131W from DC rails (130W to 146W from outlet, I have Gold rated PSU). See Re: Any modern psu's that have large 5v rails Imagine if my system was Athlon or P4 based instead .

EDIT: I kind of assumed that early P4 boards were 5V heavy and later ones 12V heavy . Maybe they are all 12V heavy.

wiretap wrote on 2020-09-21, 13:26:

There's always this option as well.. however from the reviews it looks hit or miss.

https://www.amazon.com/Athena-Power-AP-AT30-S … r/dp/B0042P2IIG

Correct. It's kind of cool those things still exist, but they're all but certain to be built to a scary standard akin to the power supplies that used to come free with cheap, unburred cases. Which is appalling given their target market is legacy medical and industrial, customers who need 100% uptime or else and are often running very expensive, hard to replace control equipment.

Startech discontinued its AT line, and even their legacy ATX lineup. I don't think there is anyone selling a period-authentic power supply for older machines, even Pentium III and up ATX machines, other than Athena.

I'd like to see some enterprising person buy the older ATX 1.3 units en masse as e-scrap, recap them, and maybe sell them for $100 each or thereabouts. That could be legitimately lucrative in a less developed eastern European country.

radiounix wrote on 2020-09-23, 13:39:

Correct. It's kind of cool those things still exist, but they're all but certain to be built to a scary standard akin to the po […]
Show full quote

wiretap wrote on 2020-09-21, 13:26:

There's always this option as well.. however from the reviews it looks hit or miss.

https://www.amazon.com/Athena-Power-AP-AT30-S … r/dp/B0042P2IIG

Correct. It's kind of cool those things still exist, but they're all but certain to be built to a scary standard akin to the power supplies that used to come free with cheap, unburred cases. Which is appalling given their target market is legacy medical and industrial, customers who need 100% uptime or else and are often running very expensive, hard to replace control equipment.

Startech discontinued its AT line, and even their legacy ATX lineup. I don't think there is anyone selling a period-authentic power supply for older machines, even Pentium III and up ATX machines, other than Athena.

I'd like to see some enterprising person buy the older ATX 1.3 units en masse as e-scrap, recap them, and maybe sell them for $100 each or thereabouts. That could be legitimately lucrative in a less developed eastern European country.

If demand is sufficient, a sufficiently skilled and fast solderer could make some money on that practically anywhere . They key word is demand . As it stands it's probably easier for the average retro joe to buy an old PSU for peanuts and pay a local shop to recap it . I am in Canada and I asked my local goto shop a ballpark price for recapping a motherboard and was told approx. 75 CAN$ . I can only imagine a PSU would cost less to do .

darry wrote on 2020-09-23, 11:18:

Most of that 105W in your build will be on 3.3 and 5V rails (pretty much only HDD, fans,CDs, floppies and maybe VGA card to a point will use 12V) . Add a disk controller card, an extra sound card or 2 and a NIC, all 3.3V/ 5V devices, and you are getting awefully close to a typical 110W/120W 3.3v/5v limits on inexpensive PSUs .

My Pentium 3 based system, under load, draws about 117W to 131W from DC rails (130W to 146W from outlet, I have Gold rated PSU). See Re: Any modern psu's that have large 5v rails Imagine if my system was Athlon or P4 based instead .

EDIT: I kind of assumed that early P4 boards were 5V heavy and later ones 12V heavy . Maybe they are all 12V heavy.

Not necessary to fill every expansion slot to have a retro gaming rig. If someone made the choice to cram the rig full of components, then invest in a more expensive PSU.

pixel_workbench wrote on 2020-09-23, 14:00:

darry wrote on 2020-09-23, 11:18:

Most of that 105W in your build will be on 3.3 and 5V rails (pretty much only HDD, fans,CDs, floppies and maybe VGA card to a point will use 12V) . Add a disk controller card, an extra sound card or 2 and a NIC, all 3.3V/ 5V devices, and you are getting awefully close to a typical 110W/120W 3.3v/5v limits on inexpensive PSUs .

My Pentium 3 based system, under load, draws about 117W to 131W from DC rails (130W to 146W from outlet, I have Gold rated PSU). See Re: Any modern psu's that have large 5v rails Imagine if my system was Athlon or P4 based instead .

EDIT: I kind of assumed that early P4 boards were 5V heavy and later ones 12V heavy . Maybe they are all 12V heavy.

Not necessary to fill every expansion slot to have a retro gaming rig. If someone made the choice to cram the rig full of components, then invest in a more expensive PSU.

I agree that my rig stands as rather loaded, but even with a more sparsely populated one, I still would not feel all that comfortable running rails at say 80% of their max spec on a low cost PSU . Additionally, rigs are subject to feature creep and I, for one,woukd not like to have to calculate power budget every time I change or add a component .

I think that unless you know exactly what you will do with it for the forseeable future and/or don't mind living on the limits, a PSU choice should be made with both margins and growth potential in mind .

If it just for testing purpose you could use a standard ATX PSU (Seasonic and Corsair make great ones) along with an ATX adapter like this one [https://x86.fr/atx2at-smart-converter/] to protect your mobo. I'm not affiliated with this project, I just happen to have one and can vouch for how nice it is !