Will add to the 386 story 2-3 more motherboards based on less popular chipsets, for completeness. […]
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Will add to the 386 story 2-3 more motherboards based on less popular chipsets, for completeness.
First in line is Matra 486SLC2 VESA based on EFAR Microsystems 82EC392, 82EC495 (relabeled OPTi 82C392, 82C495B) chipset, hidden under cool stickers with the word "PATH" written on them.
Still in great condition despite some scratches on the VLB and ISA slots which indicate some rough handling here and there.
Warranty labels still in place. Traces of small battery leak that was taken care of before causing real damage.

One day will spend the time to find what "PATH" stands for. Anyway.
The motherboard is interesting for several reasons.
The obvious ones - a mixture of rare IBM BL2 (SLC2) processor soldered on-board, 256Kb level 2 cache (unusual for 386SX class system), and a VLB interface.
EFAR chipsets are seen predominantly in cost reduced assemblies, or late hybrid 386/486/VLB ones.
The first type are perf and scalability crippled in various ways, the second type come with 25/33/40MHz clock generators instead of crystal oscillators which limits overclocking options.
This motherboard comes with up to 80MHz clock generator, but also has wiring for crystal oscillator which opens the path to overclocking and discovering where the performance peak really is.
Removed the clockgen from its socket. Soldered 4 pins. Ready to roll.
It will be great if one day i manage to obtain one of these late EFAR based mobos to test with BL3, SXL2 and standard 386DX processors. Ok, back to tpoic.
It was established in the past that the fastest 386SX class system is Alaris Leopard (OPTi 82C295) with the same IBM BL2 CPU, so i was really curious how the EFAR chipset will stack against it and handle the unusual combination of hardware this Matra motherboard is.
Only 25 and 33 MHz base frequencies are supported via jumpers, but i was able to find a 40MHz configuration. Unfortunately between warm resets the frequency drops down to 20MHz from time to time.
This was another incentive to move to crystal oscillator.
The system takes 80MHz crystal with easy, but struggled with 90MHz. No lights at 100MHz.
While my hopes for higher overclock faded quickly, at least 80MHz became reliable between resets.
All jumper configurations on max.
The AWARD 4.51 BIOS resembles 486 layout and type of options. There are quite a few timing settings.
All parameters on max except:
CACHE DATA BUFFER OUTPUT = DISABLED (best is ENABLED)
DRAM QUICK READ MODE = DISABLED (best is ENABLED)
DRAM QUICK WRITE MODE = DISABLED (best is ENABLED)
Similar to Alaris Leopard this motherboard was not happy with most VLB EIDE controllers - their DOS drivers hang during initialization.
DTC 2278E worked fine but had to be slowed down a lot which kind of defeated the point of using an EIDE controller. If nothing else it proved that 2278E is one of the most compatible guys around.
Ark1000VL works fine.
One unexpected outcome - the S3 Trio64 VLB driver hangs Windows. This is an omnipresent occurrence regardless of jumper/BIOS settings.
Happens even with the slowest possible base frequency and most conservative wait states.
Used Orchid Kelvin 64-VLB 2Mb (Cirrus Logic GD-5434) instead - slower than Trio64 in Windows, but still pretty good.
(Will double check that stuff at some point later)

benchmark results
Matra / EFAR 82EC392, 82EC495 is in the top performance tier for 386 class hardware and on par with Alaris Leopard / OPTi 82C295.
It is same or faster in some of the DOS interactive graphics tests, slightly slower in the FPU intensive ones.
Really liked this motherboard. Not an entirely trouble-free experience, but somehow it grew on me a lot.
Maybe because it is a great/better alternative than Alaris Leopard, which until now was in a class of its own in the area of all things 386SX.
Also, this was my first time with EFAR silicon that i really wanted be good, and it did.