Using a Pentium overdrive wouldn't really yield normal performance. It will be much higher in most benches compared to a 486 yet it will be bottlenecked by the board in some cases.

In any case, the BIOS settings can make as much difference as the hardware used. The tighter you can get the cache timings, the faster it will go

I think you've got it covered.
If you have other CPU's, maybe consider using a standard AMD or Intel 80486DX4-100, instead of the Overdrive CPU.
The Overdrive CPU you selected is slighty faster than a standard Intel 80486DX4-100 with 16k L1 cache or an AMD 80486DX4-100 with 8k L1 cache (this is based on some comparative benchmarks I saw on a site using doombench).
But, as smeezekitty has stated, the Overdrive CPU will be bottlenecked by the board in some cases.
Another reason why I'm saying this is that you might have some compatibility issues with some of your motherboards if you plug in the Overdrive CPU.

I also have a VLB and a PCI based 486 motherboard and performed some basic benchmark tests with Norton Sysinfo & Landmark's Speedtest.
CPU speed (not game benchmark performance) seems to be on par but, I did notice a slightly faster graphics performance on my VLB motherboard compared to my PCI based motherboard (despite both running at a FSB speed of 33Mhz). However, the type of graphics card could also be a factor as well as the BIOS settings.

PS: That Biostar MB8433UUD-A Version 2 (UMC Chipset) looks interesting in the sense that it appears to have a PS/2 port next to the old DIN keyboard connector?
How would one then fit this type of motherboard into your standard AT case?
Also, where's the battery located on this motherboard?

smeezekitty wrote:

Using a Pentium overdrive wouldn't really yield normal performance. It will be much higher in most benches compared to a 486 yet it will be bottlenecked by the board in some cases.

jesolo wrote:

I think you've got it covered. If you have other CPU's, maybe consider using a standard AMD or Intel 80486DX4-100, instead of th […]
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I think you've got it covered.
If you have other CPU's, maybe consider using a standard AMD or Intel 80486DX4-100, instead of the Overdrive CPU.
The Overdrive CPU you selected is slighty faster than a standard Intel 80486DX4-100 with 16k L1 cache or an AMD 80486DX4-100 with 8k L1 cache (this is based on some comparative benchmarks I saw on a site using doombench).
But, as smeezekitty has stated, the Overdrive CPU will be bottlenecked by the board in some cases.
Another reason why I'm saying this is that you might have some compatibility issues with some of your motherboards if you plug in the Overdrive CPU.

I also have a VLB and a PCI based 486 motherboard and performed some basic benchmark tests with Norton Sysinfo & Landmark's Speedtest.
CPU speed (not game benchmark performance) seems to be on par but, I did notice a slightly faster graphics performance on my VLB motherboard compared to my PCI based motherboard (despite both running at a FSB speed of 33Mhz). However, the type of graphics card could also be a factor as well as the BIOS settings.

I thought it was a 486 Overdrive Chip but point taken. Maybe a standard Intel DX2-66 or Intel DX4-100 would be a good starting point before I start throwing more unusual CPU's like AMD and CYRIX 133's at these boards.

jesolo wrote:

PS: That Biostar MB8433UUD-A Version 2 (UMC Chipset) looks interesting in the sense that it appears to have a PS/2 port next to the old DIN keyboard connector?
How would one then fit this type of motherboard into your standard AT case?
Also, where's the battery located on this motherboard?

I have another MB8433 and I use the PS2 mouse port, its a really tight fit .... I could always get the drill out and modify the case 😀
I was also under the impression a lot of the late 486 PCI motherboards were using socketed ODIN or DALLAS RTC chips which contain the battery.

DALLAS RTC CMOS Battery - pic property of Mau1wurf1977:)

If your interested in specific info about this board feipoa has done an exhaustive amount of research, customized the bios and rewritten the manual.

The World's Fastest 486 The World's Fastest 486
download/file.php?id=15668 Feipoa customised manual and BIOS for the Biostar MB-8433UUD motherboard

and here by Mau1wurf1977 Biostar MB-8433UUD-A

The UMC will probably be the fastest. The only faster 486 PCI chipset I know is the ALI Finali. The Intel board has no cache, but it still is a decent board.

Interesting. First time I've actually seen a motherboard with the battery in this configuration. However, after browsing a bit, I see that they were also quite common on these type of motherboards.
I've always just known about the old NiCd/NiMH batteries and the button (or coin) type batteries (normally CR2032). The latter is more common these days and is actually very easy to replace.
Both my 486 motherboards I mentioned in an earlier post use the CR2032 type.

I was actually wondering how many 486 PCI motherboards actually had a PS/2 connector (either via a cable connection or directly on the motherboard). I can't seem to find many 486 PCI motherboards that actually had a dedicated PS/2 connector.

GL1zdA wrote:

The UMC will probably be the fastest. The only faster 486 PCI chipset I know is the ALI Finali. The Intel board has no cache, but it still is a decent board.

No cache or fake cache? I have not really had a good look at the tracks and where they go.

jesolo wrote:

I was actually wondering how many 486 PCI motherboards actually had a PS/2 connector (either via a cable connection or directly on the motherboard). I can't seem to find many 486 PCI motherboards that actually had a dedicated PS/2 connector.

I think there are more than a few 486 boards that are "PS2 Ready" with tracks, solder pads/headers in place for the PS2 port to be installed. Was that an afterthought much like the 60/66MHz FSB settings that are not documented in manuals?

rgart wrote:

GL1zdA wrote:

The UMC will probably be the fastest. The only faster 486 PCI chipset I know is the ALI Finali. The Intel board has no cache, but it still is a decent board.

No cache or fake cache? I have not really had a good look at the tracks and where they go.

The DIP sockets on the photo are empty - it seems this was a popular configuration, I've seen only one of these with cache sockets populated. I own this board and it's performance is quite good in Speedsys even without cache. Also the built in IDE controller seems to be quite fast.