Replacing a P3-550 with a VIA C3 600 is a true downgrade, unfortunately.
The early C3's had an FPU that was running at half the speed of the rest of the CPU.
And even the first C3 to feature full speed FPU was considerably slower then a similarly clocked Celeron.

I got one of these, years ago - powered by the 900MHz C3. I ran 98 and ME on it; it wasn't too bad, but I wouldn't compare it to a P3 of a similar clock speed, perhaps 1/2 to 2/3 of the performance.

A 600MHz version would be a fair bit slower then a P3-550, I'd imagine.

Machine_1760 wrote:

but I like the idea of using it instead as it has integrated graphics and is completely passive

The IGP would be in the motherboard's chipset, not in the CPU. In other words, you can't gain an IGP by swapping a CPU.

C3 is just a CPU that sips power due to its simplistic design (also why it's slow).

However, the Pentium III line is around ~30-40 Watts power output. This is similar to most of today's notebook CPUs. You can cool them very quietly with a heatsink of decent size and a reduced speed 60+ mm fan.

I'm sorry Swaaye, I should have been clearer. i know that the graphics is on the motherboard (I'm not quite that clueless!!). I'm intending this to be a complete mainboard swap out, the C3 is actually soldered to the board.
The thing that draws me to this is that there are no fans required and the power requirements are so low that a passively cooled power supply is feasible. It'll be completely silent!

my current windows 98 setup is not intended to do anything intensive - it was originally a replacement for a P166 that unfortunately went the way of all flesh. I think I'm going to go ahead and use it. I'll uplaod some benchamarks later this week if anyone's interested?

Thanks for the feedback all.

Tetrium wrote:

Replacing a P3-550 with a VIA C3 600 is a true downgrade, unfortunately.
The early C3's had an FPU that was running at half the speed of the rest of the CPU.
And even the first C3 to feature full speed FPU was considerably slower then a similarly clocked Celeron.

even the latest "nehemiah" core of viac3, which has FPS running at fullspeed, is only about 10% faster than pervious cores in superpi, and still 4 times slower than a pentium3 at same clock. so its not all for the halfspeed of FPU, the structure is that slow.
viac3 at 1ghz takes over 10 minutes to calculate superpi(9min for nehemiah core), far lower efficiency than all socket7 cpus! 🤣

Anyone have any luck with two VIA Nehemiah C3's, 1.0 or 1.2 GHz, in an SMP-supported motherboard, i.e. ASUS-CUV4X-DLS?

Long ago I remember talking to VIA about it before they came out and they claimed that they would be SMP-capable.

I don't have any dual s370 to test them in so have no idea, sorry.

Edit:

noshutdown wrote:

Tetrium wrote:

Replacing a P3-550 with a VIA C3 600 is a true downgrade, unfortunately.
The early C3's had an FPU that was running at half the speed of the rest of the CPU.
And even the first C3 to feature full speed FPU was considerably slower then a similarly clocked Celeron.

even the latest "nehemiah" core of viac3, which has FPS running at fullspeed, is only about 10% faster than pervious cores in superpi, and still 4 times slower than a pentium3 at same clock. so its not all for the halfspeed of FPU, the structure is that slow.
viac3 at 1ghz takes over 10 minutes to calculate superpi(9min for nehemiah core), far lower efficiency than all socket7 cpus! 🤣

Ok, I had a look at the hwbot database, but frankly I find it troublesome to look for the data in the way I want to see it. If only I could sort a few selected CPU's (Only 1 type of core at 1 particular speed, overclocked or not but preferably at stock speeds) with just 1 benchmark and put them all in 1 table, it would make comparing a whole lot easier.

I did a SuperPi thread a while ago but having to install an OS made it quite troublesome.

But apparently the C3 does have very poor SuperPi performance.
Strangely, I remember the K6-III and even the Cyrix MII having SuperPi performance close to that of the Pentium MMX.

that's not reasonable, p55c has the best per-clock fpu performance of all socket7 cpus. i think i see a record of p55c overclocked to 112*3 taking only 6 minutes, almost on par with k6-3-500!
cyrix on the other hand seems to have the slowest fpu in all socket7s, with idt and rise sitting between amd and cyrix.

The problem with SuperPi is that I "think" the speed of the harddrive has an influence on it's outcome. The mentioned result is on an overclocked PCI bus, increasing the results.
I did check the Tillamook results (The mobile P1 MMX) and it's results are worse in relative terms, needing 6 1/2 minutes to complete SuperPi at 400Mhz.
Most non-mobile P1 MMX chips completed SuperPi in about 7 minutes at 300Mhz while the K6-III at 400Mhz completed in about 6 1/2 minutes.
Cyrix MII appears to need roughly 10 minutes at 300Mhz to complete, which makes it's FPU roughly 40% slower then P1 MMX.
I have run SuperPi on an M2 myself and remember it scored relatively better. Perhaps it had Liniar Burst enabled? I'll dig up the results when I have more time.

Edit:Just got home and found the thread. Apparently I never posted the SuperPi result of the MII.
Btw, thread is here: Post your retro computer superpi results here!