To get the idle consumption down, research for tools enabling the stop-grant mode of the CPU/chipset, and check whether they work on your board. Possibly you can even find an option to enable stop-grant mode operation (allows the processor to disconnect the FSB and put itself into a static low-power sleep mode) in your CMOS setup. On a cursory research, s2kctl seems to be a tool supporting the nForce2, but nForce2 boards often have problems properly working with the stop-grant mode, but it's worth a try.

mkarcher wrote on 2022-10-16, 14:21:

To get the idle consumption down, research for tools enabling the stop-grant mode of the CPU/chipset, and check whether they work on your board. Possibly you can even find an option to enable stop-grant mode operation (allows the processor to disconnect the FSB and put itself into a static low-power sleep mode) in your CMOS setup. On a cursory research, s2kctl seems to be a tool supporting the nForce2, but nForce2 boards often have problems properly working with the stop-grant mode, but it's worth a try.

Thanks, I didn't know about this. I have Windows 98 installed so I cannot test it right now, the patch only works with Windows XP. I will install it later and report back!

Wait, s2kctl does work under Windows 98! I had to use a slightly older version. After enabling the halt state and clicking apply, idle consumption dropped from 79w to 60w. That's so cool. How is this so little known?

Here's a link to the author's website of s2kctl: https://web.archive.org/web/20070104164612/ht … targaz0r.nm.ru/
And the version that I used is "s2kctl14b72.zip". Other versions crashed on startup.

I have now installed a Geforce 7600 GT and CPU is at 1800 MHz. Idle: 59w, gaming: 83w. The CPU fan is barely spinning in idle mode. That's really impressive for a powerful Socket A system.

Be aware for side effects, though. On my ECS K7S5A (yeah, I know, not the most highly regarded Socket A board, even though it has its cool black PCB), the hard drive performance on an otherwise idle system dropped from like 50MB/s to 5MB/s on enabling stop-grant mode. Probably because the south bridge needed to wake up the CPU for every couple of bytes read from the hard drive. If you don't notice any problems, though, keeping stop-grant mode enabled doesn't hurt your system.

Actually, it was quite well-known (at least in Germany) back in the days, tools like VCool for VIA chipsets were oftentimes used by PC enthusiasts in the early 2000 years to lower idle power and noise.

... speaking of Vcool, is there a link for the latest version (2.0) still active somewhere? I could only find v 1.8 (beta) on MajorGeeks: https://www.majorgeeks.com/files/details/vcool.html

Linoleum wrote on 2024-12-19, 16:29:

... speaking of Vcool, is there a link for the latest version (2.0) still active somewhere? I could only find v 1.8 (beta) on MajorGeeks: https://www.majorgeeks.com/files/details/vcool.html

Found it here: https://www.softking.com.tw/dl/13286/VC ... 2%BB).html
https://dl.softking.tw/9a64726332bb7fbe845894 … ool_alpha_6.zip

But please virus check it, I have no idea how reputable that site is.

mkarcher wrote on 2022-10-16, 18:05:

Be aware for side effects, though. On my ECS K7S5A (yeah, I know, not the most highly regarded Socket A board, even though it has its cool black PCB), the hard drive performance on an otherwise idle system dropped from like 50MB/s to 5MB/s on enabling stop-grant mode. Probably because the south bridge needed to wake up the CPU for every couple of bytes read from the hard drive. If you don't notice any problems, though, keeping stop-grant mode enabled doesn't hurt your system.

Actually, it was quite well-known (at least in Germany) back in the days, tools like VCool for VIA chipsets were oftentimes used by PC enthusiasts in the early 2000 years to lower idle power and noise.

I LOVED Vcool back in the day...

Mobile Athlon XP CPUs (Athlon XP-M) do support PowerNow! dynamic frequency scaling and power saving technology. I don't remember if there was "pencil mod" for turning Athlon XP into XP-M and if there was any s.A desktop motherboard that was able to use the mobile Athlon XP-M CPUs. It would be great if it is possible to use these mobile CPU power saving functions on a desktop system.

analog_programmer wrote on 2024-12-20, 11:59:

Mobile Athlon XP CPUs (Athlon XP-M) do support PowerNow! dynamic frequency scaling and power saving technology. I don't remember if there was "pencil mod" for turning Athlon XP into XP-M and if there was any s.A desktop motherboard that was able to use the mobile Athlon XP-M CPUs. It would be great if it is possible to use these mobile CPU power saving functions on a desktop system.

It's been a long time since I used my Athlon XP machine (this thread is old!), but I believe you could turn any Athlon XP into a mobile CPU by cutting or connecting some bridges, except the ones with Barton core after a certain manufacturing date, those were finally made tamper-proof by AMD. This would at least allow you to change the multiplier, but it won't give you the better silicon that real XP-M's had which allowed them to run at much lower voltages. I believe the XP-M's worked in a lot of (or all?) desktop boards, but to use the dynamic power saving features, you also need a compatible motherboard and vendor-made driver for it, the CPU won't do the throttling on its own. Desktop boards didn't have that, so this feature was only available on laptop mothboards.

As for regular desktop boards, you can only set a fixed voltage, and only few motherboards allow you to set very low voltages through the BIOS. I know of one motherboard that lets you use any voltage, even the lowest supported ones: https://theretroweb.com/motherboards/s/qdi-k7 … -k7e-kinetiz-7e
It doesn't set the core voltage in the BIOS, instead it has old-fashioned jumpers that directly manipulate the L7 bridges of the CPU. The lowest voltage that can be set using these bridges is 1.15V, I believe. I tried to boot an Athlon XP at that voltage and a speed of around 1000 MHz, and it worked. So that's another option for an ultra low-power XP machine.

CrystalCPUID can be setup to do automatic throttling on XP-M CPUs. The voltage adjustment only works if supported by the motherboard. If not, it can change the CPU multiplier only. Desktop and mobile Athlons both have designated pins for indicating to the board which voltage should be used. The issue is they use two different incompatible schemes, and desktop boards mostly only support the narrower range of voltages specified by desktop CPUs.