The VIA processor would only work on a board, such as the Shuttle AV18 V3 that has the VIA AGPSet (I have this board and the VIA C3 700A processor) since the OEM boards are locked on Pentium III and only Pentium III processors due to the BIOS code being altered to fit the manufacturers needs.

bjwil1991 wrote:

The VIA processor would only work on a board, such as the Shuttle AV18 V3 that has the VIA AGPSet

Are you sure?
I've seen quite a few C-3 builds based on boards with the Intel 440BX chipset.

I use a C3 Nehemiah on an Asus TUSL2-C, which is based on the Intel 815EP chipset.

You could also find one of the many mini-ITX boards that had these chips installed (albeit naturally you will have to deal with losing many expansion slots/etc compared to full-size boards). The original EPIA-533 and EPIA-800 boards had passively-cooled C3 Samuel2 chips soldered on, and the EPIA V variations traded one of the two IDE connectors for an FDD connector. These also used high-quality Sanyo capacitors, unlike the later Nehemiah-based >=1GHz models.

Some of the early epia boards also have built in Sound Blaster compatibility, so you wouldn’t even need a sound card.

BinaryDemon wrote:

Some of the early epia boards also have built in Sound Blaster compatibility, so you wouldn’t even need a sound card.

Yes, I've been looking at those, and I will probably get one some time in the future.

That's not really the direction I want to go with this build though.
I'm thinking of doing some case modding to show off the vintage hardware, and those boards are just too modern.

Sent you a PM.

Using a 800MHz C3 Ezra on a MSI MS-6119, which is a 440BX/Slot1 board, together with a MS 6905 Master slotket. It's the 133MHz FSB model, but works fine to run it at 100x8 MHz too.

Haven't had any problems whatsoever with that rig. Everything just works. Guessing that just about any 440BX board with a VRM that can supply the required voltage (1.35V in my case) would work with C3.

A combination like that works fine with an SE440BX-2. The Intel supplied BIOS is fairly crippled, so it's a fair indication of how an Ezra would work with OEM Slot 1 boards featuring capable enough VRMs.

I ended up just buying another motherboard - it cost about the same as a slotket, and this board is on the Via list of compatible boards.

It looks like finding a processor is going to be the difficult part.

If I'm not bothered about PI performance, and only care about 286, 386, and 486, could I use a Samuel or Samuel 2 core instead of an Ezra?

I did try reading all the benchmark stuff, but it seems to pertain mostly to the Ezra-T and Nehemiah.

A Samuel 2 800MHz has all the same options as Ezra-T but a lower top clock speed. I think it would still serve your purposes.

Equally important is whether your Motherboard can change FSB speed from 66 to 100 to 133MHz or something. When disabling processor caches memory access through FSB becomes the next limiting factor.

The manual says that it is compatible with 66, 100 and 133MHz FSB processors.

Is that what I'm looking for?

I honestly believed I was reasonably competent around old pc stuff, but this all new to me.

Does the manual have shots of the BIOS screen. Any options to manually choose the FSB clock?

50mhz FSB is of great use if your concern is lower end -- even then 286 speeds probably aren't going to happen.

66mhz FSB along with slow memory timings gives 386DX-25 performance. It's conceivable that 50mhz FSB would drop the speed equivalent down to around, say, a Harris 286-20.

I have not experimented with memory timings, whatsoever so perhaps that is why.

With my Ezra (866 rated chip) clocked at its lowest 150mhz (50x3.0) and cache disabled I had the following benchmarks:

8.6 3DBench; 2.7 PC Player Bench; 7.87 SpeedSys, and 3.84FPS in Doom. You are saying other settings (memory) could noticeably decrease speeds further?

IIRC, yes, by about 5-10%.

gdjacobs wrote:

IIRC, yes, by about 5-10%.

I don't imagine that would take my lowest benchmarks posted above into 286 territory.

Other results indicate the real performance of a 286 is about 10-20% slower than a 386DX of equivalent clock.
download/file.php?id=26613&mode=view

With full SETMUL slowdown options in play at 66mhz FSB, my C3 can achieve performance approximating a 386DX-25 as per NSSI. I anticipate 50mhz FSB and degraded memory timings will deliver fast 286 performance, but I'd love to hear your results.