Nice!

TELVM wrote:

Overkill. With only one of the two Athlon MP drawing from +5V, I doubt that mobo will draw even 20A (100W) from +5V.

It would be very easy to exceed 100W on +5v with this combination.
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As previously discussed the MP's use up to 88 watts.
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A hard drive and CD drive would use about 2 amps on 5v so that's another 10 watts.
That's already 98 watts just for the CPU and drives.
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The slot specifications require the slots be capable of providing 2 amps of +5v per slot. (And 2 amps of +3.3v when applicable.)
Obviously few cards use the full allotment and probably all slots won't be filled but add-in cards are still a significant load on 3.3v and 5v.
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RAM is also on either 3.3v or 5v.
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This varies quite a lot but 3.3v and 5v motherboard loads (on-board IC chips) is typically between 20 and 40 watts.
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So, if we use the average of 30 watts for motherboard loads + 88 wtts (CPU) + 10 watts (drives) that is already 128 watts
WITH ZERO ADD-IN CARDS and NO RAM with this PSU --- 140w - 128w = 12w
How much RAM, video card, sound card and drive controller are you going to power with 12 watts?
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You cab get away with such setups so long as things don't hit full load at the same time.....
.... but is that a good plan for a gaming system?
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The problem would be the same even for single CPU systems with powerful-ish CPUs that power the CPU from +5v.
It' is the whole reason CPU power is now on 12v.
Such systems simply need A LOT of 5v.
I've seen alexanrs try to explain this several times (not all in this thread) and he's right. But few people pay attention or get it.
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D

The PSU is noisy?
I don't recall EA-650's being noisy.
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D

saturn wrote:

Most would say no. I want this system as quite as possible and I had it left over from a old sever I got rid of. I may as well t […]
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PCBONEZ wrote:

The PSU is noisy?
I don't recall EA-650's being noisy.
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Most would say no. I want this system as quite as possible and I had it left over from a old sever I got rid of. I may as well toss it in.

I'm on the lookout for a good psu with a better 5v rail. But until I find a newer psu with a 120mm fan I'll stick with what I have. I'll only be putting the system at about 75% load max. A old psu with a 30 amp 5v rail is probably not going to do a hole lot better do to aging caps.
If anyone has any idas on psu let me know. I only know of some sea sonic and pc power & cooling units with strong 5v rails.

Caps in PSU's is usually an easy job and it doesn't need to be old, it just needs healthy 3.3v and 5v rails.

The usual problem with more modern PSUs is by the time you get into the range that has healthy 3.3 & 5 volt rails the total watts is high and the amps on +12v can be insane for an older PC.
Much of the blame for the situation goes to the industry pushing high end video cards.
AFAIAC all it does is make things unnecessarily expensive for people that don't want high end video cards.

I will make a recommendation later. After the auction I'm tracking closes. 🤣 🤣 🤣
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F-it. - Here
http://www.ebay.com/sch/i.html?_odkw=CORSAIR+ … 29+-V2&_sacat=0
Yeah, WAY over-kill on the 12v but that's the price of using newer spec PSUs for older spec systems.
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One of my standard searches. - Sometimes I get lucky and snag one for $35-$40-ish shipped.
The prices jump up and down a lot so getting a good price is all about the right place at the right time.
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I'm wondering about NOS OEM replacements. Which models of Dell or Compaq machine from that era had power supplies that:
came with standard ATX connectors?
were of quality design from the likes of Delta?

As PCBONES stated, any new PSU with VRM based 5V rails is going to be way overblown, and I'm unsure of the quality of ATX12V 1.3 options on the market today. I see units by Startech and Rosewill based on initial Google-fu.

The fiercest Athlon MP was 66W TDP. These relic comps draw little power empirically.

"I used to run my Dual AthlonMP on a cheap "Sparkle" brand 300- or 325-watt 🤣 power supply. I finally did get the machine to overload the power supply, but I had to have both chips fully loaded, both hard drives running, be reading from the DVD-ROM, *and* burning a DVD on the other drive all at the same time. Unless I did all of that at once, it would run like a champ."

http://www.tomshardware.co.uk/forum/160107-29 … rements#3372410

gdjacobs wrote:

I'm wondering about NOS OEM replacements. Which models of Dell or Compaq machine from that era had power supplies that:
came with standard ATX connectors?
were of quality design from the likes of Delta?

Might not seem like it but that's a really broad question.
Dell and HP/Compaq don't actually build PSUs anymore they outsource them to OEMs. I think IBM too now.
They have used quite a number of OEMs over the years including Delta, ACBel, Astec, NPS, Sparkle, FSP, HiPro, Liteon, Seasonic, Zippy.
In some cases one PC model may have PSUs by made by multiple different OEMs and of course which OEMs they favor changes over time.
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Those for the consumer and business markets tend to be light duty (not cheap quality, just low wattage) but those from servers/workstations would do well for this.
Naturally there is a dud model here and there but for the most part they are good quality builds.
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Most old Deltas are real troopers. I pulled one out of an old skt-478 a while ago. The inside was packed with dust bunnies and the air intake was totally clogged but it didn't care, didn't even overheat - just kept chugging along.
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TELVM wrote:

The fiercest Athlon MP was 66W TDP. These relic comps draw little power empirically.

Ah, yeah.
If you read back my numbers were adjusted for VRM efficiency.
TDP is not what it pulls from the PSU it' what it pulls from the VRM.

And I wouldn't consider anyone that thinks Sparkle is a low-end brand to know what they are talking about.
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From the first page of this thread:

havli wrote:

I'm not sure about A7M266-D VRM configuration, but my Tyan Tiger MPX draws power from both 5V and 12V rail. Half of the VRM are connected to 5V (first socket) and the rest to 12V (second socket). Two Palominos 1600+ measured power consumption (CPUs only) is 95W combined on both 5V and 12V line (12,2A @ 4,56V + 3,2A @ 11,77V). That system was working flawlessly using 460W Delta PSU with 21A @ 5V and 15A @ 12V CPU / 11A @ 12V (second rail).

^ The 62.8W TDP Athlon MP 1600+ draws 12.2A (61W) from +5V. A 21A max +5V rail gets the job done.

TELVM wrote:

From the first page of this thread:

havli wrote:

I'm not sure about A7M266-D VRM configuration, but my Tyan Tiger MPX draws power from both 5V and 12V rail. Half of the VRM are connected to 5V (first socket) and the rest to 12V (second socket). Two Palominos 1600+ measured power consumption (CPUs only) is 95W combined on both 5V and 12V line (12,2A @ 4,56V + 3,2A @ 11,77V). That system was working flawlessly using 460W Delta PSU with 21A @ 5V and 15A @ 12V CPU / 11A @ 12V (second rail).

^ The 62.8W TDP Athlon MP 1600+ draws 12.2A (61W) from +5V. A 21A max +5V rail gets the job done.

OP has MP 1800+ which are 66 watts each.
Adjusted for 75% VRM efficiency one 1800+ would pull 88 watts from the PSU. - 75% VRM efficiency is pretty lenient as I would expect 65-70% for a system this old.
88 watts would be 17.6 amps so a PSU with 21a on 5v would have a whopping 3.4a left for all other 5v loads -IF- you loaded the +5v to 100%.
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One thing the OP can try to alleviate this issue, if the motherboard allows, is undervolting. This might lower the processor's power draw a bit and give the PSU more breathing room.

I don't know if you could even find one these days but one I've used that would work is an FSP460-60PFN. (aka: FSP460-60PN)
Good chance you'll need to replace some caps but these are really solid PSUs. And I don't mean just heavy - which they are.
They are EPS12V (Server class.) There is a review here: http://www.xbitlabs.com/articles/cases/displa … fsp-psu_10.html
The 5v rail is 29a and the 3.3v/5v combined is 200 watts.
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alexanrs wrote:

One thing the OP can try to alleviate this issue, if the motherboard allows, is undervolting. This might lower the processor's power draw a bit and give the PSU more breathing room.

I've actually thought about building something like this to convert some of the excess 12v to 5v. I would use schottky diodes to prevent a ground loop and to ensure the 5v from the PSU dips low before this kicks in to boost it, and of course need some filtering to take care of noise.
http://www.ebay.com/itm/400801183658
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I've seen some packaged to fit into drive bays but those were WAY too expensive for me.
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D

PCBONEZ wrote:

I've actually thought about building something like this to convert some of the excess 12v to 5v. I would use schottky diodes to […]
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alexanrs wrote:

One thing the OP can try to alleviate this issue, if the motherboard allows, is undervolting. This might lower the processor's power draw a bit and give the PSU more breathing room.

I've actually thought about building something like this to convert some of the excess 12v to 5v. I would use schottky diodes to prevent a ground loop and to ensure the 5v from the PSU dips low before this kicks in to boost it, and of course need some filtering to take care of noise.
http://www.ebay.com/itm/400801183658
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I've seen some packaged to fit into drive bays but those were WAY too expensive for me.
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That is a very interesting idea, actually. Having a little device that transfers some of the load to the 12V rails would make building retro Athlon systems much easier. What I meant, though, was undervolting the processor itself, providing it 1.7V or 1.65V instead of the 1.75V it asks for, thus lowering its power consumption.

D

The 2800+ Barton has a lower TDP than the 1800+ Palomino, so no cons here.