darry wrote on 2020-05-20, 16:59:

TorqueDaisy wrote on 2020-05-20, 15:29:

I believe it. the TX-650W runs it all OK with 30 on the 3.3/5 but it doesnt POST until I start strapping extra drives to it, fun times.

My guess is it wants a minimum load on the 12V before it's happy enough flip power-good to ON .

I wonder if I will have the same issue with the RM850x . My P3 system has practically no 12V load .

There's multiple versions of the TX650 - some of them appear to be based on older designs that separately regulate the 12V and lower voltages, it's entirely possible that those will have cross-load issues when 12V load is low.

The current RMx series models (and indeed, most 80+ Gold or better PSUs) instead use DC-DC conversion for 5V and 3.3V, where the power supply only generates 12V, and the other voltages are converted from the 12V. No problem with only loading the 5V on one of those. The Corsair CX series is also notable for being some of the few Bronze rated PSUs that use DC-DC conversion.

kepstin wrote on 2020-05-21, 13:34:

darry wrote on 2020-05-20, 16:59:

TorqueDaisy wrote on 2020-05-20, 15:29:

I believe it. the TX-650W runs it all OK with 30 on the 3.3/5 but it doesnt POST until I start strapping extra drives to it, fun times.

My guess is it wants a minimum load on the 12V before it's happy enough flip power-good to ON .

I wonder if I will have the same issue with the RM850x . My P3 system has practically no 12V load .

There's multiple versions of the TX650 - some of them appear to be based on older designs that separately regulate the 12V and lower voltages, it's entirely possible that those will have cross-load issues when 12V load is low.

The current RMx series models (and indeed, most 80+ Gold or better PSUs) instead use DC-DC conversion for 5V and 3.3V, where the power supply only generates 12V, and the other voltages are converted from the 12V. No problem with only loading the 5V on one of those. The Corsair CX series is also notable for being some of the few Bronze rated PSUs that use DC-DC conversion.

Thanls . I knew DC-DC converters were becoming more popular (even suggested that hooking one up externally to a 12v rail might be useful for more 3.3 / 5v power from modern PSUs), I did not realize they were that common now on gold plus units .

kepstin wrote on 2020-05-21, 13:34:

darry wrote on 2020-05-20, 16:59:

TorqueDaisy wrote on 2020-05-20, 15:29:

I believe it. the TX-650W runs it all OK with 30 on the 3.3/5 but it doesnt POST until I start strapping extra drives to it, fun times.

My guess is it wants a minimum load on the 12V before it's happy enough flip power-good to ON .

I wonder if I will have the same issue with the RM850x . My P3 system has practically no 12V load .

There's multiple versions of the TX650 - some of them appear to be based on older designs that separately regulate the 12V and lower voltages, it's entirely possible that those will have cross-load issues when 12V load is low.

The current RMx series models (and indeed, most 80+ Gold or better PSUs) instead use DC-DC conversion for 5V and 3.3V, where the power supply only generates 12V, and the other voltages are converted from the 12V. No problem with only loading the 5V on one of those. The Corsair CX series is also notable for being some of the few Bronze rated PSUs that use DC-DC conversion.

This is super insightful and informative, I was not aware that there were different designs internally in that fashion! This TX650 was from my build in 2010 and it's definitely getting up there in years, so it makes sense that it would be as you described. I will probably keep the CX450 and use that for this build and use the TX650 for my server since the supply in that one just kicked the bucket in the last few days.

Thanks!

I installed my RM850x today and gave it spin in 3DMARK 2001 at 1600x1200 . It peaked at 146 Watts at the outlet with an average of about 130 Watts , all under load. When idle in DOS, I get about 90 Watts at the outlet . So, considering that represents less than 20% load, efficiency should be somewhere between 87 % and 90 % . That means peak power draw was, at most, about 131 Watts with an average of about 117 Watts under load .

Almost all of that is on 3.3V and 5V rails (main 12V user is probably my FX 5900 , other 12V "users" include 2 floppy drives and a DVD-ROM drive along with 3 case fans ) .

I feel I am cutting it a bit close, but I guess over-current protection will kick-in if ever things get too intense .

Just saw a reference in another thread to the risks of using overspecced PSUs on low powered devices in the context of ATX to AT converters.

I see a potential parallel with using overspecced ATX PSUs on ATX builds, especially in the context of a possible partial short on the 12V rail .

Re: ATX to AT PSU requirements for AT Socket 7 with Pentium MMX 200 MHz???

bloodem wrote on 2020-04-25, 18:00:

In Romania I found these and so far I bought like.... 6 or 7 of them (30 amps on the 5V rail, up to 180W, extremely quiet,Thunderbird 1.4 GHz works flawlessly together with a GeForce 3 Ti 200).
But not sure if you can find them in any other countries.

Hello! I live in Romania. Any problem with the Segoteps so far? I want to put together an XP build with a high end GIGABYTE socket A board with a 4 pin and a 20 pin (btw do I plug the 4 pin CPU into the 4 pin on the board?) and an Athlon Thunderbird 1800 or Duron Spitfire 800. I will use 348MB of SDRAM or 512MB DDR1 depending on what the board supports and only an ATI Rage Pro Turbo AGP for now. With a 200GB IDE HDD.
My problem is that my 600BQ by EVGA can only to 20 Amps on 5V and even my old MSI MS 6340 MB doesn't post. only posts with the old 230w PSU which has bad caps.

Centigrams wrote on 2023-02-05, 09:49:

Hello! I live in Romania. Any problem with the Segoteps so far? I want to put together an XP build with a high end GIGABYTE socket A board with a 4 pin and a 20 pin (btw do I plug the 4 pin CPU into the 4 pin on the board?) and an Athlon Thunderbird 1800 or Duron Spitfire 800. I will use 348MB of SDRAM or 512MB DDR1 depending on what the board supports and only an ATI Rage Pro Turbo AGP for now. With a 200GB IDE HDD.
My problem is that my 600BQ by EVGA can only to 20 Amps on 5V and even my old MSI MS 6340 MB doesn't post. only posts with the old 230w PSU which has bad caps.

Hai, salut! 😀
No problem so far with any of the Segoteps.
There are no Thunderbirds 1800, so I imagine you're referring to either a Palomino or a Thoroughbred Athlon XP.
Anyway, the Segotep should work very well, I have multiple Pentium 3/Athlon/Athlon XP builds with this PSU.

Salut!
Yes, my bad it is a Thoroubred CPU. Though I plan on getting some Palomino chip.
I might purchase a Segotep as a Socket A test bench.
But I have found that if I buy a board with a 4 pin CPU (12V) it only requires a PSU with 20A on 5V. Which would make my EVGA 600BQ work. Philscomputerlab talked about it. https://www.youtube.com/watch?v=141Q4-UklIA
It is towards the end of the vid. He ran a Palomino CPU and a good GPU. Around 7:23.
I think I will purchase a GIGABYTE 7NF-RZ. Do you have any experiences with it?

Hello, I had some troubles which were documented here and led me to this thread: PC shuts down after 30 seconds - 1 minute - Solved: Premier LC-300-ATX PSU at fault

Basically I need a modern PSU, but as a beginner I'm totally lost as to what I should be searching for. I need it for an ATX Pentium III Coppermine build. Could anyone please point me out to some of the cheaper/reliable models, or at least explain the specs that I need to check for while searching for a newer ATX PSU (wattage, voltage rails needed, etc.)? Btw, how do you connect floppy drives to these modern PSUs? Through a molex - floppy power adapter?

Thank you in advance for all your advice and help!

A pentium 3 build doesn't need a strong v5 psu.

Nemo1985 wrote on 2023-06-04, 21:42:

A pentium 3 build doesn't need a strong v5 psu.

i have some local options to choose from, a Corsair VS 350, a VS 550, a CX 430 and a CV 450. The prices are very similar, so what would be the better option?

Also, as a beginner I have to ask: how would I connect a floppy drive to these PSUs? Will a simple molex to floppy power adapter do the trick?

Most of those psu already have a floppy connector, if you need more you have to rely on adapters.
Check the datasheet and go for the oe with highest v3.3 and v5 amps and you are good to go.
Personally I usually go with evga 80 bronze 450watt.

Again that's much more than what you need for a pentium 3 build.

Edit: that's what you need to check, the higher, the better

:

Nemo1985 wrote on 2023-06-04, 22:05:

Most of those psu already have a floppy connector, if you need more you have to rely on adapters. Check the datasheet and go for […]
Show full quote

Most of those psu already have a floppy connector, if you need more you have to rely on adapters.
Check the datasheet and go for the oe with highest v3.3 and v5 amps and you are good to go.
Personally I usually go with evga 80 bronze 450watt.

Again that's much more than what you need for a pentium 3 build.

Edit: that's what you need to check, the higher, the betterbr_psu_power_chart_450w_LRG.jpg:

Thank you so much, found the exact EVGA model you mentioned. I just want something modern that works. My PSU started giving me problems and I have to start preparing for when the others follow suit. In case I only manage to get a Corsair model, would it be such a difference in terms of reliability vs. EVGA Bronze?

andre_6 wrote on 2023-06-04, 22:16:

Nemo1985 wrote on 2023-06-04, 22:05:

Most of those psu already have a floppy connector, if you need more you have to rely on adapters. Check the datasheet and go for […]
Show full quote

Most of those psu already have a floppy connector, if you need more you have to rely on adapters.
Check the datasheet and go for the oe with highest v3.3 and v5 amps and you are good to go.
Personally I usually go with evga 80 bronze 450watt.

Again that's much more than what you need for a pentium 3 build.

Edit: that's what you need to check, the higher, the betterbr_psu_power_chart_450w_LRG.jpg:

Thank you so much, found the exact EVGA model you mentioned. I just want something modern that works. My PSU started giving me problems and I have to start preparing for when the others follow suit. In case I only manage to get a Corsair model, would it be such a difference in terms of reliability vs. EVGA Bronze?

I have no idea, I tried to find info about the rails of psu corsair but I wasn't able to find any info about that on the website. Classic Corsair hiding useful information so they can change the spces without notice.
Just check psus with good amperage and combined power. As long as they are new you shouldn't have any particular issue.

Nemo1985 wrote on 2023-06-04, 22:20:

andre_6 wrote on 2023-06-04, 22:16:

Nemo1985 wrote on 2023-06-04, 22:05:

Most of those psu already have a floppy connector, if you need more you have to rely on adapters. Check the datasheet and go for […]
Show full quote

Most of those psu already have a floppy connector, if you need more you have to rely on adapters.
Check the datasheet and go for the oe with highest v3.3 and v5 amps and you are good to go.
Personally I usually go with evga 80 bronze 450watt.

Again that's much more than what you need for a pentium 3 build.

Edit: that's what you need to check, the higher, the betterbr_psu_power_chart_450w_LRG.jpg:

Thank you so much, found the exact EVGA model you mentioned. I just want something modern that works. My PSU started giving me problems and I have to start preparing for when the others follow suit. In case I only manage to get a Corsair model, would it be such a difference in terms of reliability vs. EVGA Bronze?

I have no idea, I tried to find info about the rails of psu corsair but I wasn't able to find any info about that on the website. Classic Corsair hiding useful information so they can change the spces without notice.
Just check psus with good amperage and combined power. As long as they are new you shouldn't have any particular issue.

Will do, like I said in my original thread with my problems, I had no idea even these modern PSUs had floppy connectors. I just hope that they have enough molex connectors for the HDD, and both CD drives

andre_6 wrote on 2023-06-04, 22:23:

Nemo1985 wrote on 2023-06-04, 22:20:

andre_6 wrote on 2023-06-04, 22:16:

Thank you so much, found the exact EVGA model you mentioned. I just want something modern that works. My PSU started giving me problems and I have to start preparing for when the others follow suit. In case I only manage to get a Corsair model, would it be such a difference in terms of reliability vs. EVGA Bronze?

I have no idea, I tried to find info about the rails of psu corsair but I wasn't able to find any info about that on the website. Classic Corsair hiding useful information so they can change the spces without notice.
Just check psus with good amperage and combined power. As long as they are new you shouldn't have any particular issue.

Will do, like I said in my original thread with my problems, I had no idea even these modern PSUs had floppy connectors. I just hope that they have enough molex connectors for the HDD, and both CD drives

Check the info of the psus you are interested it's the way to go, usually the website has all the info you need to pick the right one before buy.

Nemo1985 wrote on 2023-06-04, 22:28:

andre_6 wrote on 2023-06-04, 22:23:

Nemo1985 wrote on 2023-06-04, 22:20:

I have no idea, I tried to find info about the rails of psu corsair but I wasn't able to find any info about that on the website. Classic Corsair hiding useful information so they can change the spces without notice.
Just check psus with good amperage and combined power. As long as they are new you shouldn't have any particular issue.

Will do, like I said in my original thread with my problems, I had no idea even these modern PSUs had floppy connectors. I just hope that they have enough molex connectors for the HDD, and both CD drives

Check the info of the psus you are interested it's the way to go, usually the website has all the info you need to pick the right one before buy.

I will, really hope I can get the EVGA. Thank you for your help!

bloodem wrote on 2020-04-25, 18:00:

In Romania I found these and so far I bought like.... 6 or 7 of them (30 amps on the 5V rail, up to 180W, extremely quiet,Thunderbird 1.4 GHz works flawlessly together with a GeForce 3 Ti 200).
But not sure if you can find them in any other countries.

@bloodem

How are the "Segotep ATX-500WH" PSUs holding up ??

I found (also in RO) this Segotep PSU that is somehow even cheaper :"ATX-500W12 "
And somehow states 200W on +5V & +3.3V, although it has the same 30Amps as the "ATX-500WH" which states only 180W.

B24Fox wrote on 2023-09-22, 10:37:

@bloodem […]
Show full quote

@bloodem

How are the "Segotep ATX-500WH" PSUs holding up ??

I found (also in RO) this Segotep PSU that is somehow even cheaper :"ATX-500W12 "
And somehow states 200W on +5V & +3.3V, although it has the same 30Amps as the "ATX-500WH" which states only 180W.

No issues to report! I'm using them in many retro PCs and they have been reliable so far. However, that combined 180W power is most likely misleading. Especially when used with a Thunderbird 1.4 GHz + a power hungry GPU, the voltage on the 5V rail can drop down to ~4.7V. It does still work and there is no instability, but it's clearly a bit too much for it (especially if you are planning on using such a system long term).
But for lower power Athlon XP systems with GeForce 4 Ti 4400 or similar GPUs, they work great!

I don't own/haven't used the ATX-500W12. It's probably similar, but it also might not be (considering that it has a lower price).

Just tested the Segotep ATX-500W12 PSU, that i got the other day, and here are the results for the 5V rail:

Test rig:
CPU: Palomino AthlonXP 2000+ (70 Watts)
MB: MSI K7T266 Pro2 v2.0
Ram: 1x 256MB DDR
1x HDD
1x FDD

With: PixelView GeForce3Ti 500 (measurements with multimeter)
- during 3dMark2000 - Helicopter run, High details, 1280x1024x32 => 4.86 Volts
- during idle in BIOS menu => 4.91 Volts

With: Voodoo2 - 12MB + Cirrus Logic GD5436 - 2MB (measurements with multimeter)
- during Soldier of Fortune - gameplay, 800x600 Hidetails & nomipmap => 4.80 Volts with 130.1W power draw at the 220V wall outlet
- during Prime95 [in place large FFT's] => 4.78 Volts with 136.8W power draw at the 220V wall outlet
- during idle in BIOS menu => 4.89 Volts

During all the testing:
The ATX 5V red wires got pretty warm to the touch
The PSU kinda smelled like something was heating up (although it only blew cool air, and the case was only warm in certain spots)
The 12V rail was between 12.69V - 13V (same as my cheap-o old mid-2000s PSU that i usually run this test rig on)

*Measurements were compared between 3 multimeters.