• Please review our updated Terms and Rules here

Upgrading/retrofitting modern PSUs in vintage computers

digger

digger

Experienced Member
Joined
Jul 9, 2008
Messages
395
Location
Amsterdam, the Netherlands
Hi everyone,

As you know, power supplies (at least the ones from reputable manufacturers) have generally become much more power-efficient and reliable over the years.

I was wondering if it would make sense to retrofit high efficiency ATX PSUs into vintage computers, for several reasons:

  • better power efficiency (hey, we all need to watch both the environment and our wallets, especially those of us with "private museums" in our basements ;))
  • less heat (and in some cases better airflow as well, due to smaller PSUs and better fans)
  • cleaner power output (good for the health of the machine overall)
  • more long-term reliability (again, assuming you don't use crappy stuff)
  • adjusted for newer national voltage levels (for instance: in most of western Europe, the official voltage has gone up from 220V to 230V, a change that took place within the last two decades)
  • less noise and interference
  • increased safety due to stricter regulations
  • more available power (particularly important when other add-ons have already pushed the total power consumption of a system near the limit of its original PSU, or if there was little margin to begin with)
  • (in some cases) automatic switching between regional voltages and frequencies (100-250V, 50-60Hz)

I may be overstating the virtues of performing such an upgrade, and some purists might consider it out of the question, but it is true that in old computers the power supply unit is often one of the first components to fail. Heck, I remember from my days working in computer retail that the PSU was often an overlooked cause of hardware failure and stability problems even in recent systems.

Since vintage computer cases are often bigger than newer systems (due to miniaturization), and generally require the same typical DC voltages (mostly 5V and 12V, although I know there are exceptions), it seems practical to do this.

Opinions and anecdotes are very welcome. :)
 
Last edited:
Absolutely possible. There are adapters from ATX->AT and from AT->ATX, and even ATX splitters so you can power two machines from the same PSU provided you can get enough juice from it. To do this you could just buy an ATX->AT power adapter and go to town.

http://www.atxpowersupplies.com/ATX-to-AT-Converter.php

(Above site has all of the above and more, iirc)
 
Raven said:
Absolutely possible. There are adapters from ATX->AT and from AT->ATX, and even ATX splitters so you can power two machines from the same PSU provided you can get enough juice from it. To do this you could just buy an ATX->AT power adapter and go to town.

http://www.atxpowersupplies.com/ATX-to-AT-Converter.php
Click to expand...

Thanks raven. I was aware of the existence of such adapters, but what I would like to know is what others here think about proactively upgrading the PSU (not just as an improvised fix after a vintage PSU has actually failed, but even if its still working, as an upgrade), simply for the possible advantages that I listed.
 
Yes, you can do it. But I'm really of two minds on the subject. I have two big issues with modern ATX power supplies.

1. Mostly, they're built like crap, designed for a couple of years tops of service. That being said, I've got a couple of Compaq server supplies from about 2002 that are built like tanks. Completely nonstandard enclosure and pinout, as you'd expect.
2. Lack of a "hard power" switch--the thing is always connected to the AC line, even when it's "off". I'd be tempted to bridge the "soft" power switch and retrofit the PCB into the old enclosure, complete with switch on the AC mains.

If you do decide to use a new ATX supply, make sure that the +5 line can support the current demand of your system. Some newer systems are heavy on the +3.3V and +12V side and a little light on +5.

On the other hand, the benefit is that many have much quieter (i.e. temperature controlled) cooling fans.

But heck, the CPU board for a "vintage" system probably uses less than 30 watts, so what point is greater efficiency?
 
Chuck(G) said:
Yes, you can do it. But I'm really of two minds on the subject. I have two big issues with modern ATX power supplies.

1. Mostly, they're built like crap, designed for a couple of years tops of service.
Click to expand...
Are there that few high quality (retail) PSU manufacturers, then?

2. Lack of a "hard power" switch--the thing is always connected to the AC line, even when it's "off". I'd be tempted to bridge the "soft" power switch and retrofit the PCB into the old enclosure, complete with switch on the AC mains.
Click to expand...

Actually, most ATX PSUs that I've encountered have a hard (circuit breaking) switch on the back (in addition to the soft power-on mechanism that they indeed always seem to have).

If you do decide to use a new ATX supply, make sure that the +5 line can support the current demand of your system. Some newer systems are heavy on the +3.3V and +12V side and a little light on +5.
Click to expand...
Good to know. Thanks for sharing this.

On the other hand, the benefit is that many have much quieter (i.e. temperature controlled) cooling fans.
Click to expand...

Of course this only applies to systems with an internal actively cooled PSU.

But heck, the CPU board for a "vintage" system probably uses less than 30 watts, so what point is greater efficiency?
Click to expand...

That's one of the reasons why I opened this thread. How much could be saved given the increased efficiency? If it's merely a single digit percentage, then it obviously wouldn't be worth it (at least not as long as the original PSU hasn't failed yet).
 
Just about any medical-equipment-rated power supply should be okay. The good ones will have active PFC and publish their efficiency and test data.

In the consumer-level power supplies, I like Seasonic. They seem to give me trouble-free operation.

As far as how much you'll save over other measures, that's difficult to say without knowing your operating configuration and usage patterns. Do you run your systems 24x7? Do any have older (5.25") hard drives (you might be better off swapping in a newer low-power drive or flash device)?
 
If it predates the IBM PC I would say try to repair the original. However that may not be possible. I got a Zorba 2000 off eBay several years ago. About 1 hour after I powered it up the power supply burned out due to a short in the video section. It tried, but couldn't repair it. Finally gave up and found a newer replacement.

Chuck
 
Last edited:
digger said:
That's one of the reasons why I opened this thread. How much could be saved given the increased efficiency? If it's merely a single digit percentage, then it obviously wouldn't be worth it (at least not as long as the original PSU hasn't failed yet).
Click to expand...

The difference is probably negligible. PSU efficiency varies with the load, and newer models will be optimised to be most efficient at the kinds of load a modern PC would draw. They're not all that efficient at low loadings like the <100W old AT (and earlier) computers need.

Voltage changes aren't really a big deal either. The old 220V and 240V systems both allowed +/- 10%, so switching to 230V is still within range for both.
 
Last edited:
digger said:
Hi everyone,

As you know, power supplies (at least the ones from reputable manufacturers) have generally become much more power-efficient and reliable over the years.

I was wondering if it would make sense to retrofit high efficiency ATX PSUs into vintage computers, for several reasons:

  • better power efficiency (hey, we all need to watch both the environment and our wallets, especially those of us with "private museums" in our basements ;))
  • less heat (and in some cases better airflow as well, due to smaller PSUs and better fans)
  • cleaner power output (good for the health of the machine overall)
  • more long-term reliability (again, assuming you don't use crappy stuff)
  • adjusted for newer national voltage levels (for instance: in most of western Europe, the official voltage has gone up from 220V to 230V, a change that took place within the last two decades)
  • less noise and interference
  • increased safety due to stricter regulations
  • more available power (particularly important when other add-ons have already pushed the total power consumption of a system near the limit of its original PSU, or if there was little margin to begin with)
  • (in some cases) automatic switching between regional voltages and frequencies (100-250V, 50-60Hz)

I may be overstating the virtues of performing such an upgrade, and some purists might consider it out of the question, but it is true that in old computers the power supply unit is often one of the first components to fail. Heck, I remember from my days working in computer retail that the PSU was often an overlooked cause of hardware failure and stability problems even in recent systems.

Since vintage computer cases are often bigger than newer systems (due to miniaturization), and generally require the same typical DC voltages (mostly 5V and 12V, although I know there are exceptions), it seems practical to do this.

Opinions and anecdotes are very welcome. :)
Click to expand...

Another advantage would be that, in the future, it would be easier to replace an ATX PSU then an AT PSU.
Personally I'd prefer to use older ATX PSU's from reputable manufacture for several reasons:
-Since they are about the same age of the newest AT PSU's, they have (or should have) compatible volt rails.
-They are easy for me to find and dirt cheap now. You can still find them in old computers or even second hand stores for a few Euro's
-Seasonic is good but I prefer to use FSP's. They are relatively silent, easy to find (were used extensively back in the P2 and P3 days) and help cool the case better then Seasonic's.
-Last but not least, I think the FSP's of that era are better build then the generic "Target, Codegen, Hippo" and other no-name ultra-light crappy brand AT PSU's I do own.

I once ordered 5 of those adapters from Ebay.com (United States, so shipping was kinda very costly) but those came with a hard switch :)
I will be using these adapters for my upcoming retro builds.

I wouldn't worry about the possible savings when using more efficient PSU's. You might save like 5W per hour, not really worth it imo
 
While we're all touting our favorite PSU brands, mine is Antec. Rock solid unit, served me for years and still is through three systems.
 
You must log in or register to reply here.
Back
Top