I mean, yeah but, I don't imagine any PSU would have problems with a 233MMX regardless..

You are right.
My point was more about to recommend EVGA models if you want a modern PSU instead of old periodic correct ones.

Others I found do not have enough power on 3.3V/5V, not a 20-pin mainboard connector or lack of molex/floppy connectors.

So what would be the maximum reasonable build with such a PSU? PIII / Duron / Athlon up to 1GHz?

Aui wrote on 2024-02-06, 08:00:

So what would be the maximum reasonable build with such a PSU? PIII / Duron / Athlon up to 1GHz?

I used Corsair CX450M happily with my Slot1/P3 800MHz Coppermine/GF2 GTS and it has 110W combined for both 3.3V and 5V rails and max 20A for both. It has separate rails, so it is not group regulated.

However, I built 1400MHz TB with Abit KG7 RAID and Radeon 8500 in that case and as that MB doesn’t have 12V VRM, it means that the PSU would be woefully underpowerd for the 5V loads that system introduced. So, I recapped old Enermax PSU for that system.

However, if you build a Socket A platform with a motherboard which has 12V VRM, you can use modern 12V optimized PSUs quite fine and using faster Thoroughbreds and Bartons aren’t out of the question.

Your power consumption on different rails depends on other components too, such as GPU. For example, Radeon 9700 cards are 5V heavy and GF FX5900 series is significantly more 12V heavy.

If I find time I can test another rig of mine with that EVGA 450 BR PSU (20A @3.3V/5V, 120W combined).

That would be:
- ASUS TUSL2-C board
- PIII-S 1.4GHz
- 512MB SDRAM
- SSD (via IDE->SATA adapter)
- DVD-ROM drive
- Voodoo5 5500 (uses approx. 30W power via molex connector)
- Audigy 2 ZS sound card
- Diamond MX300 sound card

I assume that EVGA power supply can handle this without problems too.

crusher wrote on 2024-02-06, 13:34:

If I find time I can test another rig of mine with that EVGA 450 BR PSU (20A @3.3V/5V, 120W combined). […]
Show full quote

If I find time I can test another rig of mine with that EVGA 450 BR PSU (20A @3.3V/5V, 120W combined).

That would be:
- ASUS TUSL2-C board
- PIII-S 1.4GHz
- 512MB SDRAM
- SSD (via IDE->SATA adapter)
- DVD-ROM drive
- Voodoo5 5500 (uses approx. 30W power via molex connector)
- Audigy 2 ZS sound card
- Diamond MX300 sound card

I assume that EVGA power supply can handle this without problems too.

Can you please provide some Multimeter measurements of the +5V rail while this computer is running 3dMark2000 ?
And also for the "Pentium MMX 233MHz" build that you already have?

It would be very useful to see how the "EVGA 450 BR" behaves when the entire PC in under load.

My K6/2+ system pulls almost 120W from the wall. Not to mention when the CDrom starts reading, it pulls an extra ~1.5A of power on 5V.
So 100W 120W for both 5V & 3.3V, (as the "EVGA 450 BR" offers) would be VERY kind of on the limit.

Unfortunalety I have no working multimeter at home right now.
I maybe can do so later.

EVGA 450 BR has 120W combined for 5V+3.3V (you wrote 100W).

crusher wrote on 2024-02-06, 14:48:

Unfortunalety I have no working multimeter at home right now.
I maybe can do so later.

EVGA 450 BR has 120W combined for 5V+3.3V (you wrote 100W).

Oops!
I corrected my post, thanks! 😀

120W off the wall for your K6-2+ system. Hmm that's much.
Reading the specs your K6-2 should consume about 30W as well as a 233 MHz MMX PIII-S 1.4GHz.
There should be enough room for ISA/PCI cards and hard/optical drives.
Do you have any special components in your system?

crusher wrote on 2024-02-06, 14:59:

120W off the wall for your K6-2+ system. Hmm that's much. Reading the specs your K6-2 should consume about 30W as well as a 233M […]
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120W off the wall for your K6-2+ system. Hmm that's much.
Reading the specs your K6-2 should consume about 30W as well as a 233MHz MMX.
There should be enough room for ISA/PCI cards and hard/optical drives.
Do you have any special components in your system?

The CPU is OC'd to 550MHZ which should be about 18W IIRC. And also 2 HDDs, 1 CDrom, 1 FDD, Audigy 2 ZS+Front Panel, Voodoo5 (which pulls from both +12V & +5V).
All those actually running at the same time, pull quite a lot from the wall (granted, not only from the 5V rail).
But although 80% of the time, nobody uses the computer in such a manner (everything at once) .. we should still be mindful of max consumption, especially with 5V high wattage CPUs like PIII and expecially AthlonXP.

Just playing Carmageddon 2, which has CD track Audio, can suck an extra 7W on the 5V rail, compared to other games that don't use the CD.

Alright, I saw an EVGA model that has 24A @3.3V, 20A €5V, 150W combined. I don't remember the 12V.
I will search and post it here...

@B24Fox:

Maybe these EVGA models are of interest for you (sorted lowest to highest power).
Have a look into the "Specs" tab.

https://www.evga.com/products/product.aspx?pn=100-W1-0600-K1
https://www.evga.com/products/product.aspx?pn=100-BR-0600-K1
https://www.evga.com/products/product.aspx?pn=110-BQ-0650-V1
https://www.evga.com/products/product.aspx?pn=100-BR-0700-K1
https://www.evga.com/products/product.aspx?pn=110-BQ-0750-V1
https://www.evga.com/products/product.aspx?pn=110-BQ-0850-V1
https://www.evga.com/products/product.aspx?pn=220-GT-1000-X1
https://www.evga.com/products/product.aspx?pn=220-GT-1300-X1
https://www.evga.com/products/product.aspx?pn=220-GP-1600-X1 <- this monster has 25A@3.3V/5V, combined 150W, 133A @12V

Because it certainly makes sense to buy a 1600W power supply just to get 25 amps on the 5V rail...
I get that modern DC-DC designs are technically superior in every way, but a decent PSU (potentially recapped if necessary) from 2005-2009 is more than good enough.

Each to their own.
I personally have a bad feeling when using a >20 years old PSU in my retro systems.
I've had 2 periodic correct old PSUs that quit working from one moment to the other.
Not powering the pc on any more is one thing.
To blow up something or damaging my beloved partially nowadays rare hardware is another.
Not to imagine the worst scenario of causing a fire when I'm not at home.

For me the 450W EVGA model is sufficient.

In general I agree that using a >1000W PSU just to have 150W @3.3V/5V is somewhat heavy.
But if you are concerned in safety I guess one has no other choice.

crusher wrote on 2024-02-07, 10:48:

Each to their own. I personally have a bad feeling when using a >20 years old PSU in my retro systems. I've had 2 periodic corre […]
Show full quote

Each to their own.
I personally have a bad feeling when using a >20 years old PSU in my retro systems.
I've had 2 periodic correct old PSUs that quit working from one moment to the other.
Not powering the pc on any more is one thing.
To blow up something or damaging my beloved partially nowadays rare hardware is another.
Not to imagine the worst scenario of causing a fire when I'm not at home.

For me the 450W EVGA model is sufficient.

In general I agree that using a >1000W PSU just to have 150W @3.3V/5V is somewhat heavy.
But if you are concerned in safety I guess one has no other choice.

Using a 1000W PSU for 100W load is not exactly very wise (and possibly not even safe) either.

appiah4 wrote on 2024-02-07, 10:53:

Using a 1000W PSU for 100W load is not exactly very wise (and possibly not even safe) either.

I'm not doing this 😉
I'm using 450W PSU to have max. 120W load on 3.3V/5V.
Some other member was asking for more because 120W is not enough.
I think the 700W EVGA model would be a good compromise for 150W max. load on 3.3V(24A) and 5V(20A).

I'm using this PSU since years, I have 3 of them and it's a current production. Known brand, OK price and good 5V rail (27A): https://www.lc-power.com/fileadmin/user_uploa … 3_datasheet.pdf

I power dual Athlon MPs + Matrox Parhelia without any issue.

The only thing is that you have to buy some SATA to Molex/Floppy adapters on aliexpress, it has mostly SATA connectors or whatever these are really called.

Nice values!
Thanks for the tip, Minutemanqvs.

SATA->Molex/Floppy adapters should not be the problem.

crusher wrote on 2024-02-07, 09:56:

@B24Fox: […]
Show full quote

@B24Fox:

Maybe these EVGA models are of interest for you (sorted lowest to highest power).
Have a look into the "Specs" tab.

https://www.evga.com/products/product.aspx?pn=100-W1-0600-K1
https://www.evga.com/products/product.aspx?pn=100-BR-0600-K1
https://www.evga.com/products/product.aspx?pn=110-BQ-0650-V1
https://www.evga.com/products/product.aspx?pn=100-BR-0700-K1
https://www.evga.com/products/product.aspx?pn=110-BQ-0750-V1
https://www.evga.com/products/product.aspx?pn=110-BQ-0850-V1
https://www.evga.com/products/product.aspx?pn=220-GT-1000-X1
https://www.evga.com/products/product.aspx?pn=220-GT-1300-X1
https://www.evga.com/products/product.aspx?pn=220-GP-1600-X1 <- this monster has 25A@3.3V/5V, combined 150W, 133A @12V

Thanks crusher, but only the models above 100oW seem to have over 20A on the +5V rail. So it doesn't really seem feasible, or budget friendly 😉
And also I now remember why I said 100W and not 120W... It's because 120W is for both +5V & +3.3V.
And the +5V rails has only 20A, which amounts to exactly 100W.

A few pages back I praised the "Segotep ATX-500WH" recommended by @bloodem (said he's using this model for a few years on an AthlonXP)
It (supposedly)has 30A on the +5V rail
After I tested a few segotep models, I went and bought 3 of this model for about 25EURO each.. So very cheap IMO

But I know the specs don't always tell the full story, and I don't imagine for a second that this Segotep can ACTUALLY deliver 30W on the +5V rail.
That's why I'm very curious for multimeter measurements from your EVGA 450-BR 😀

Minutemanqvs wrote on 2024-02-07, 11:43:

I'm using this PSU since years, I have 3 of them and it's a current production. Known brand, OK price and good 5V rail (27A): https://www.lc-power.com/fileadmin/user_uploa … 3_datasheet.pdf

I power dual Athlon MPs + Matrox Parhelia without any issue.

The only thing is that you have to buy some SATA to Molex/Floppy adapters on aliexpress, it has mostly SATA connectors or whatever these are really called.

This actually seems pretty decent!
Priced similar as the EVGA 450-BR; but has 7 extra Amps on the +5V rail!

Any chance you can do some multimeter readings of the +5V rail on your AthlonMP system, while runing Prime95 ?? (presuming you're running an OS that supports multiple CPU threads)

Not easy to measure the total current on four +5 on a ATX with one meter.... I know you can pull a pin out and check, that would give a good average per leg and should be same on all 4. so 4x meter.....
Be a bit tough to pull all 4 to meter and back to 4... most Digi's have a 10amp max for like 15 seconds max (or some such thing) or at least mine does on the high current range.....

added: my Corsair CX750 has 25amp on the +5v, yes only 130watt combined with 3.3v but Athlon boards do not use much 3.3v....
I think using (one of if multi) the 12v rail on newer PSU and 5v buck converter is a good way to add more current....