i had to abandon the idea of a fast Socket A computer because of this. The pull from the 5v rail is insane and there is no modern power supply below u$s 150 that can sustain that (i refuse to use 20years+ PSU's)

zuldan wrote on Yesterday, 22:47:

Ouch! What make/model PSU is that?

It's a Codegen "520W" model - rated with 42 amps on 5V (the real limit would be 30 amps, as that's the rating of the 5V rectifier diode). A not so great PSU. However I don't want to go through the efforts of checking ancient CPUs, when going to 12V for the CPU is possible. I halt my overclocking until the 12V mod is done. No need to risk anything.

Living wrote on Today, 02:03:

i had to abandon the idea of a fast Socket A computer because of this. The pull from the 5v rail is insane and there is no modern power supply below u$s 150 that can sustain that (i refuse to use 20years+ PSU's)

Well.. fast Socket A is a wild range. If you overclock in extreme ranges, the CPU consumes just a hecking lot of power. Here's 2V VCore + SuperPi 1M on an A7N8X - this is the 5V rail:

We're having 4.86V at the ATX connector with a current draw of 34A - which results in 165,24W of power going into that board

Ozzuneoj wrote on Yesterday, 22:11:

I doubt I would ever do anything like that, but I find the idea totally fascinating. I'd love to see pictures and read about how you do it.

How thoroughly have setups like this been tested? Are there any long-term negatives to doing this aside from the usual stress of overclocking on the CPU?

I wouldn't see any serious issues with that. They've been proven during overclock to run with 12V for the VRM just fine.

STM specifically states that L6917B (used both on the A7N8X and K7S8X) is capable to run with 12V just fine. You'll get a drop in efficiency though.

Living wrote on Today, 02:03:

i had to abandon the idea of a fast Socket A computer because of this. The pull from the 5v rail is insane and there is no modern power supply below u$s 150 that can sustain that (i refuse to use 20years+ PSU's)

Hi,

You might not need to abandon that idea just based on that, while most Socket A motherboards use 5 Volts to derive the CPU and other voltages there are some, especially later boards that use the 12 volts rail for that. Unfortunately most motherboards doesn't have: "I use 12V" printed on it (or even in the manual), but there are various online lists that you can check for example:
https://www.vogonswiki.com/index.php/List_of_ … _A_motherboards
Note: That unlike what the name suggests, that site is not officially affiliated or run by vogons.org. Also as it is a Wiki, while it requires registration which suggest that the data is more reliable than for a Wiki not needing it, it might still be inaccurate.

MagefromAntares wrote on Today, 05:41:

Hi, […]
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Living wrote on Today, 02:03:

i had to abandon the idea of a fast Socket A computer because of this. The pull from the 5v rail is insane and there is no modern power supply below u$s 150 that can sustain that (i refuse to use 20years+ PSU's)

Hi,

You might not need to abandon that idea just based on that, while most Socket A motherboards use 5 Volts to derive the CPU and other voltages there are some, especially later boards that use the 12 volts rail for that. Unfortunately most motherboards doesn't have: "I use 12V" printed on it (or even in the manual), but there are various online lists that you can check for example:
https://www.vogonswiki.com/index.php/List_of_ … _A_motherboards
Note: That unlike what the name suggests, that site is not officially affiliated or run by vogons.org. Also as it is a Wiki, while it requires registration which suggest that the data is more reliable than for a Wiki not needing it, it might still be inaccurate.

Oh, nice! I guess I'd forgotten that my Abit NF7-S had a 12v VRM... it's been a while since I've heard much about that.

Just so I'm clear on this... Does that mean that a high powered (or overclocked) CPU in a board like that doesn't increase the +5v rail requirement at all and instead puts the entire CPU load on the +12v rail of the PSU?

Along those same lines, does a Socket A board using a +12v VRM change anything with regard to powering AGP or PCI cards that don't have auxiliary power connectors? Or is this only relating to CPU load?

Ozzuneoj wrote on Today, 06:04:

Oh, nice! I guess I'd forgotten that my Abit NF7-S had a 12v VRM... it's been a while since I've heard much about that. […]
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MagefromAntares wrote on Today, 05:41:

Hi, […]
Show full quote

Living wrote on Today, 02:03:

i had to abandon the idea of a fast Socket A computer because of this. The pull from the 5v rail is insane and there is no modern power supply below u$s 150 that can sustain that (i refuse to use 20years+ PSU's)

Hi,

You might not need to abandon that idea just based on that, while most Socket A motherboards use 5 Volts to derive the CPU and other voltages there are some, especially later boards that use the 12 volts rail for that. Unfortunately most motherboards doesn't have: "I use 12V" printed on it (or even in the manual), but there are various online lists that you can check for example:
https://www.vogonswiki.com/index.php/List_of_ … _A_motherboards
Note: That unlike what the name suggests, that site is not officially affiliated or run by vogons.org. Also as it is a Wiki, while it requires registration which suggest that the data is more reliable than for a Wiki not needing it, it might still be inaccurate.

Oh, nice! I guess I'd forgotten that my Abit NF7-S had a 12v VRM... it's been a while since I've heard much about that.

Just so I'm clear on this... Does that mean that a high powered (or overclocked) CPU in a board like that doesn't increase the +5v rail requirement at all and instead puts the entire CPU load on the +12v rail of the PSU?

Along those same lines, does a Socket A board using a +12v VRM change anything with regard to powering AGP or PCI cards that don't have auxiliary power connectors? Or is this only relating to CPU load?

I think these lists are about the primary VRM of the motherboard, so it suggest that the whole CPU power comes from the 12V regulator, although this doesn't preclude the possibility of having a secondary VRM powering the cards or various chips from a different rail. According to the front page of vogonswiki.com, even if that page is not officially affiliated with vogons.org many of the contributors of that Wiki are also members of this forum, so someone who helped put together that list might read this and can confirm if this page were put together with the possibility of a secondary VRM present or just considered the power requirements of the CPU.

Ozzuneoj wrote on Today, 06:04:

Oh, nice! I guess I'd forgotten that my Abit NF7-S had a 12v VRM... it's been a while since I've heard much about that. […]
Show full quote

MagefromAntares wrote on Today, 05:41:

Hi, […]
Show full quote

Living wrote on Today, 02:03:

i had to abandon the idea of a fast Socket A computer because of this. The pull from the 5v rail is insane and there is no modern power supply below u$s 150 that can sustain that (i refuse to use 20years+ PSU's)

Hi,

You might not need to abandon that idea just based on that, while most Socket A motherboards use 5 Volts to derive the CPU and other voltages there are some, especially later boards that use the 12 volts rail for that. Unfortunately most motherboards doesn't have: "I use 12V" printed on it (or even in the manual), but there are various online lists that you can check for example:
https://www.vogonswiki.com/index.php/List_of_ … _A_motherboards
Note: That unlike what the name suggests, that site is not officially affiliated or run by vogons.org. Also as it is a Wiki, while it requires registration which suggest that the data is more reliable than for a Wiki not needing it, it might still be inaccurate.

Oh, nice! I guess I'd forgotten that my Abit NF7-S had a 12v VRM... it's been a while since I've heard much about that.

Just so I'm clear on this... Does that mean that a high powered (or overclocked) CPU in a board like that doesn't increase the +5v rail requirement at all and instead puts the entire CPU load on the +12v rail of the PSU?

Along those same lines, does a Socket A board using a +12v VRM change anything with regard to powering AGP or PCI cards that don't have auxiliary power connectors? Or is this only relating to CPU load?

Yes. The CPU (only) is powered by the 12V rail - other components might be, but usually they're powered from 3.3V and 5V. This lifts a heavy load off the 5V rail. It only affects the power of the CPU. Naturally though, the 5V rail of all slots and the CPU power are shared, meaning the voltage drop to and in the board will be significantly lower if the CPU is not using 5V anymore. That would leave more headroom (less voltage drop on the 5V rail) for the expansion slots. I'm not sure if that really makes a difference in practice though.

In normal operation (not extreme overclocking) I'd say it's not a big deal.

VanillaFairy wrote on 2026-07-04, 23:33:

Haven't tried booting it as a floppy since I'm getting tired and I'd rather wait just for the IDE DVD-RW drive I have on the way to arrive, but I tried setting it to 500MiB and it still won't boot...
To be fair I wouldn't be surprised if part of the issue was me using a USB keyboard, but I don't have any PS/2 keyboards to try with anyway.

Hooo boy this disk drive might also be dead.

it at least detects there is a disk in it, and spins the disk too even, but it can't seem to read any of the disks I've burnt; it waits a minute or so and then repeats the same "DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER" error.
I guess the laser could be dirty, or maybe it hates the Phillips DVD-Rs I got, or maybe something else is broken...
(For reference, it is a LG GH22LP20 that I got)

Do you have a way to extract the Vista CD onto the hard drive? Then you could make the drive bootable with bootsect.exe and run the installer from there, without the need to boot from CD or USB.

Could you explain your setup a bit more? I'm not sure if I understood it right, you have a retro PC with IDE only, and it has a SATA SSD connected over an adapter? And the only other PC is a modern one that has no SATA/IDE at all? If so, how did you get anything at all onto the SSD?

asdf53 wrote on Today, 15:52:

Do you have a way to extract the Vista CD onto the hard drive? Then you could make the drive bootable with bootsect.exe and run the installer from there, without the need to boot from CD or USB.

I do have the ISO already, and even got it booting off a CF card but then it complained about not detecting any system volume information. when the installer was the thing that formatted the SSD.
Also can't get the Plop boot manager booting from the DVD-Rs either. currently the only thing I have been able to boot is when I put an already-installed Alpine Linux onto the SSD. (and I guess also Ventoy but I couldn't get anywhere from there)

Could you explain your setup a bit more? I'm not sure if I understood it right, you have a retro PC with IDE only, and it has a SATA SSD connected over an adapter? And the only other PC is a modern one that has no SATA/IDE at all? If so, how did you get anything at all onto the SSD?

I have a retro PC with IDE only, it does have USB ports but cannot boot from them, and the SATA SSD is connected with an adaptor.
The other PC is my daily driver with no IDE, it does have SATA ports (one of them is connected to a big hdd I impulse-bought, the other's empty) but I just used a USB-to-SATA adaptor to put files onto it. (and previously a USB to CFcard adaptor when I was trying to use CF cards.)

Then you could connect the SSD to your main PC and follow this guide to copy the Vista installation files to it and make it bootable. When done, put it back into your retro PC and boot from it to start the installation.