I don't really do low power systems so this goes against my way of thinking, but

Any P4 would be a powerhouse for a WinME system. so you could go with whichever has the lowest power consumption but it's not like the fastest will cause any compatibility issues so that's what I would choose myself.

Out of your list of Graphics cards I'd go with Nvidia just because they typically have better compatibility. Again I see no point going slower for what would be marginal power savings.
And faster cards will allow you enable higher resolutions or driver enhancements like AA

tarik wrote on 2025-08-26, 23:13:

My goal is to build a low-power system

478 is the worst platform you can choose for this purpose. You are better off with a 370 or 775 Core2 CPU for this. Anyway i would look into the listings of cpu world for low TDP and pick one of that. It may be a celeron though. If i were required to pick from your list, i would choose the 3GHz CPU and the Radeon 9600 Pro.

Second that. Look for a Pentium M So479 motherboard if you want a low-power system from similar era with similar performance.
P4 CPUs have a TDP similar to modern mid- to high end CPUs, but with far less power management. They basically run hot all the time they're on.

If "low" power is the main criterion, you have two Prescott CPUs and one Northwood in the list. Prescott runs hotter than Northwood at same speed & performance, so the 2.4GHz Northwood (512kB cache) would be the least excessively hot of the three. Pentium M CPUs have about 50% more IPC (i.e. are about 50% faster for a given clock speed) than Pentium 4, so a 2GHz Pentium M would be equivalent to a 3GHz P4, but at a TDP of 21W instead of 59W (for the 2.4GHz Northwood) to 89W (3GHz Prescott)

For GPUs it's a similar story - the R9800Pro is definitely the fastest of the lot but also the hottest. Probably the 9600Pro gives you best performance per Watt.

chinny22 wrote on 2025-08-27, 01:16:

I don't really do low power systems so this goes against my way of thinking, but […]
Show full quote

I don't really do low power systems so this goes against my way of thinking, but

Any P4 would be a powerhouse for a WinME system. so you could go with whichever has the lowest power consumption but it's not like the fastest will cause any compatibility issues so that's what I would choose myself.

Out of your list of Graphics cards I'd go with Nvidia just because they typically have better compatibility. Again I see no point going slower for what would be marginal power savings.
And faster cards will allow you enable higher resolutions or driver enhancements like AA

The reason I want low power consumption is because it produces less heat and lasts longer.

AncapDude wrote on 2025-08-27, 02:14:

tarik wrote on 2025-08-26, 23:13:

My goal is to build a low-power system

478 is the worst platform you can choose for this purpose. You are better off with a 370 or 775 Core2 CPU for this. Anyway i would look into the listings of cpu world for low TDP and pick one of that. It may be a celeron though. If i were required to pick from your list, i would choose the 3GHz CPU and the Radeon 9600 Pro.

I already have a Pentium 3 and Voodoo 3 system for that purpose. This one is a different system. I want a powerful CPU, but a low-power and reliable graphics card so it won’t break. Actually, the system I want is quite clear—maybe I just didn’t explain it well. In general, powerful graphics cards tend to fail, but CPUs and motherboards are much more durable and easier to repair. That’s why I want an older operating system with a strong CPU for 1998–2002 games. For this, I need the coolest-running graphics card possible.

Then go with the MX440, some of them are passively cooled. Make sure there is airflow though.

I have examined the benchmark tests of the Intel Pentium E6700 CPU, and it’s a processor that everyone seems to overlook. Its single-core performance is surprisingly fast. Link: https://www.cpubenchmark.net/cpu.php?cpu=Inte … 3.20GHz&id=1106”

This system of mine has Windows XP installed, and with my ATI FireGL X3 256 MB AGP card—which Phil tested in his video—it’s incredibly powerful and the driver support works perfectly. What I mean is, I already have a DOS, Glide, or high-performance XP system. What I’m currently working on is building the coolest-running PC possible for Windows ME and games from 1998–2002. Maybe now I’ve explained myself better. 😀

For cool low-power P4 I would go with Cedar Mill. Its 'D0' stepping has a TDP of only 65 W.
But they are only available in the S775 version, and you already have a motherboard (s478) and several processors to choose from.
So it's not an option anyway...

I recommend choosing Athlon XP experience with a motherboard that can undervolt CPUs.

tarik wrote on 2025-08-27, 10:59:

chinny22 wrote on 2025-08-27, 01:16:

I don't really do low power systems so this goes against my way of thinking, but […]
Show full quote

I don't really do low power systems so this goes against my way of thinking, but

Any P4 would be a powerhouse for a WinME system. so you could go with whichever has the lowest power consumption but it's not like the fastest will cause any compatibility issues so that's what I would choose myself.

Out of your list of Graphics cards I'd go with Nvidia just because they typically have better compatibility. Again I see no point going slower for what would be marginal power savings.
And faster cards will allow you enable higher resolutions or driver enhancements like AA

The reason I want low power consumption is because it produces less heat and lasts longer.

then go for a Sempron 754.

I understand what you are saying in general, but IMO what you are trying to do makes very little sense.

If you want as reliable and low power as possible you have to go as new as possible. Everything P4/S478 is about as bad for what you want as it gets - hot and within the time of multiple widely known hardware defects, like capacitor plague.

In a sense the system you already have, E6700+X800 based one, should be good for what you want - late 98/early XP. You should be able to run 9x on it and it will be much better than anything P4/S478. By the way it is not nearly powerful enough to be "high-performance XP system", that would be something much later like LGA1155+GTX6xx/GTX7xx. As good as X800 is for its time it will not run crysis...

Archer57 wrote on 2025-08-27, 13:03:

I understand what you are saying in general, but IMO what you are trying to do makes very little sense.

If you want as reliable and low power as possible you have to go as new as possible. Everything P4/S478 is about as bad for what you want as it gets - hot and within the time of multiple widely known hardware defects, like capacitor plague.

In a sense the system you already have, E6700+X800 based one, should be good for what you want - late 98/early XP. You should be able to run 9x on it and it will be much better than anything P4/S478. By the way it is not nearly powerful enough to be "high-performance XP system", that would be something much later like LGA1155+GTX6xx/GTX7xx. As good as X800 is for its time it will not run crysis...

You’re right, calling it high performance would be an exaggeration. What I actually meant was that within the AGP era, a card based on the X800 could be considered “high” for that time—of course, not counting the GeForce 6 series. I don’t think undervolting would make much of a difference on a Pentium 4. I don’t have an Athlon system either. So, with what I currently have, I think the most reasonable choice is the Pentium 4 2.4 GHz with 512 KB cache and a 533 MHz bus, the 65-watt version. I could install Windows ME along with Windows 2000.

I really like the E6700 AGP-slot machine, because it has the old AGP slot while still being much closer to modern systems. Also, it’s actually one of the best single-core performers, but since people often make judgments without looking at test results, it tends to be overlooked.

Low power and P4 don't go together, looks like the 512k 2.4 is a Northwood which has a significantly lower TDP than the Prescott - and the 3.0GHz 800FSB would seem to be a P4 HT - and while the HT won't be useful for a single threaded OS, it actually has a slightly lower TDP than the 2.4 Prescott.
Also, probably worth using an idle cooler such as RAIN to force the CPU into a low power state when idling

Matth79 wrote on 2025-08-27, 13:52:

Low power and P4 don't go together, looks like the 512k 2.4 is a Northwood which has a significantly lower TDP than the Prescott - and the 3.0GHz 800FSB would seem to be a P4 HT - and while the HT won't be useful for a single threaded OS, it actually has a slightly lower TDP than the 2.4 Prescott.
Also, probably worth using an idle cooler such as RAIN to force the CPU into a low power state when idling

I’ve seen that the Pentium 4 3.0 GHz (1 MB cache, 800 MHz FSB) is rated at 89W TDP, while the Pentium 4 2.4 GHz (512 KB cache, 533 MHz FSB) is listed at 65W TDP. Among the three CPUs I mentioned earlier, it’s really confusing to determine which one actually has the lowest power consumption.

I'll echo some of the other comments here that trying to build a low power system based on the Pentium 4 platform is a bit contradictory, especially when including Prescott based Pentium 4 CPUs as options.

For Pentium 4 , a slower Northwood processor like the 2GHz models have TDP of about 52-54W.

A better option would be ditching the P4 platform and going with a mobile Athlon XP or Sempron build.

Shponglefan wrote on 2025-08-27, 14:29:

I'll echo some of the other comments here that trying to build a low power system based on the Pentium 4 platform is a bit contradictory, especially when including Prescott based Pentium 4 CPUs as options.

For Pentium 4 , a slower Northwood processor like the 2GHz models have TDP of about 52-54W.

A better option would be ditching the P4 platform and going with a mobile Athlon XP or Sempron build.

How many watts of power do these processors actually consume?

tarik wrote on 2025-08-27, 15:39:

How many watts of power do these processors actually consume?

Is your goal actually low power (as I think any P4 build is low power compared to modern gaming PCs), or is it that you just want a quiet system?

If the latter, I'd be inclined to just replace stock fans with something like Noctua, and use a modern PSU that stops the fan under low loads

Graphics Card Idle Power Load Power TDP Total System Idle Total System Load
GeForce4 MX 440 128-bit 10–15 W 25–30 W ~30 W 40–50 W 85–95 W
GeForce FX 5500 128-bit 15 W 30–35 W ~35 W 45–50 W 90–100 W
GeForce FX 5600 128-bit 15–20 W 35–40 W ~40 W 45–55 W 95–105 W
GeForce FX 5700 128-bit 20 W 45 W ~45 W 50–55 W 105–110 W
Radeon 9550 128-bit 15 W 30 W ~30 W 45–50 W 90–95 W
Radeon 9600 Pro 128-bit 20 W 40–45 W ~45 W 50–55 W 100–110 W
Radeon 9600 XT 128-bit 25 W 50 W ~50 W 55–60 W 105–115 W
Radeon 9800 Pro 128-bit 25 W 55 W ~55 W 55–60 W 115–120 W

RetroPCCupboard wrote on 2025-08-27, 15:45:

tarik wrote on 2025-08-27, 15:39:

How many watts of power do these processors actually consume?

Is your goal actually low power (as I think any P4 build is low power compared to modern gaming PCs), or is it that you just want a quiet system?

If the latter, I'd be inclined to just replace stock fans with something like Noctua, and use a modern PSU that stops the fan under low loads

I want both silence and longevity in terms of heat. The main goal is actually to build a system for games from the 1998–2002 era.