I once had one of these boards, but it was dead and I couldn't get it working. I am pretty sure the manufacturer's name was Sunnyvale Labs, but I can't seem to find any information on it. PCchips M921 looks identical, so it was most likely a case of badge engineering.

1) You might want to consider 150MHz, it's usually faster.
2) If you use jumpers for FSB settings, there might be undocumented options out there. Just check the FSB block for jumper positions following the same logic, but missing in the manual. It can be risky though.

Anonymous Coward wrote on 2020-03-28, 04:47:

I once had one of these boards, but it was dead and I couldn't get it working. I am pretty sure the manufacturer's name was Sunnyvale Labs, but I can't seem to find any information on it. PCchips M921 looks identical, so it was most likely a case of badge engineering.

Thinking of the SYL8884? - this thread mentions it (with links) and the ST1A REV B

TD-4IP-UMC-AIO PCI Socket 3 Motherboard

PC Hoarder Patrol wrote on 2020-03-28, 05:14:

Anonymous Coward wrote on 2020-03-28, 04:47:

I once had one of these boards, but it was dead and I couldn't get it working. I am pretty sure the manufacturer's name was Sunnyvale Labs, but I can't seem to find any information on it. PCchips M921 looks identical, so it was most likely a case of badge engineering.

Thinking of the SYL8884? - this thread mentions it (with links) and the ST1A REV B

TD-4IP-UMC-AIO PCI Socket 3 Motherboard

It seems my board is very close to the one or may be the same. I happened to remember that in the late 1990’s SOYO 486 PCI board was very popular in Korea and I heard that mine is also made by SOYO. It could be.
I nearly figure out how to set jumpers except for CPU type part. I don’t understand how to to set up 1-2, 3-4 and so on. It’s like a puzzle to me.

RacoonRider wrote on 2020-03-28, 05:07:

1) You might want to consider 150MHz, it's usually faster.
2) If you use jumpers for FSB settings, there might be undocumented options out there. Just check the FSB block for jumper positions following the same logic, but missing in the manual. It can be risky though.

How will be the performance between 150MHz and 160MHz?
150MHz : FSB 50MHz and 3x, PCI should be 1/2 resulting 25MHz (there is only 1: and 1:1/2 setup)
160MHx : FSB 40MHz and 4x, PCI 40MHz OC or 20MHz (1/2 of FSB)

I plan to use PCI video card/VOODOO2 and PCI UW scsi board. PCI speed difference may affect
performance.

I have a similar system configurable via front panel switches to multipliers 3 or 4 and bus speeds 25MHz, 33MHz, 40MHz, 50MHz. I can get a fast benchmark of any combination if you like. PCI:FSB ratio is 1. Are you interested in any particular software?
Full spec:
Am5x86-133ADZ
AOpen AP43 (512Kb L2 cache)
64MB RAM
Matrox Mystique 2Mb
etc.

Concerning Voodoo 2 on a 486: it's not a good idea. Even the fastest 486 will not be enough for any 3dfx card. I used to have a 233MHz PentiumMMX with a Voodoo Graphics card and even at maximum clock I could squeeze out of the system, it still sometimes felt underpowered for Glide gaming. Then I got a 450MHz Pentium II and 2xVoodoo2 and GLide stuff started to really shine.

RacoonRider wrote on 2020-03-28, 07:32:

I have a similar system configurable via front panel switches to multipliers 3 or 4 and bus speeds 25MHz, 33MHz, 40MHz, 50MHz. I […]
Show full quote

I have a similar system configurable via front panel switches to multipliers 3 or 4 and bus speeds 25MHz, 33MHz, 40MHz, 50MHz. I can get a fast benchmark of any combination if you like. PCI:FSB ratio is 1. Are you interested in any particular software?
Full spec:
Am5x86-133ADZ
AOpen AP43 (512Kb L2 cache)
64MB RAM
Matrox Mystique 2Mb
etc.

Concerning Voodoo 2 on a 486: it's not a good idea. Even the fastest 486 will not be enough for any 3dfx card. I used to have a 233MHz PentiumMMX with a Voodoo Graphics card and even at maximum clock I could squeeze out of the system, it still sometimes felt underpowered for Glide gaming. Then I got a 450MHz Pentium II and 2xVoodoo2 and GLide stuff started to really shine.

There is no particular S/W in mind. As written above I wonder how will be the performance of three system - AMD 5x86 150MHz/PCI 25MHz, AMD 5x86 160MHz/PCI 20MHz and AMD 5x86 160MHz/PCI 40MHz.

It seems I can get max. 512kB L2 cache according to information found in PC Hoarder Patrol shared link.

TD-4IP-UMC-AIO PCI Socket 3 Motherboard

It says L2 cache was upgraded to 512kB using 4 UMC UN611014BU-15. Current cache memory installed on my board is 4 GMC6512-15 and 1 TK62256-15. Should I change TK62256 and to which?

No, TK62256 is TAG RAM, you do not need to change that. For 512K cache with your board, you'd have to use 4 1024k cache chips. Rare, expensive, and does not change pretty much anything in terms of performance for a 486.

It's only needed to make RAM over 32 MB (WB) or 64 MB (WT) cacheable and let's be honest, 32MB is already overkill for a 486. That's true for my chipset (SIS 496/497), it might be different for UMC.

Okay, I checked the sources and it turns out that I was wrong and PCI divider on SIS496/497 is automatically set at 1 at 25/33MHz FSB and 1/2 at 40/50MHz FSB.

Here are the benchmark results for Phil's benchmark suite from January, 2014:

CPU______PCI_____3Dbench__PCplayer_Quake__Doom(lower is better)
133MHz___33MHz___63.9_____19.6_____12.3___1759
160MHz___20MHz___77.1_____23.7_____14.8___1468
150MHz___25MHz___84.2_____24.6_____14.8___1366

RacoonRider wrote on 2020-03-28, 09:09:

Okay, I checked the sources and it turns out that I was wrong and PCI divider on SIS496/497 is automatically set at 1 at 25/33MH […]
Show full quote

Okay, I checked the sources and it turns out that I was wrong and PCI divider on SIS496/497 is automatically set at 1 at 25/33MHz FSB and 1/2 at 40/50MHz FSB.

Here are the benchmark results for Phil's benchmark suite from January, 2014:

CPU PCI 3Dbench PCplayer Quake Doom(lower is better)
133MHz 33MHz 63.9 19.6 12.3 1759
160MHz 20MHz 77.1 23.7 14.8 1468
150MHz 25MHz 84.2 24.6 14.8 1366

Wow. Thanks!

Interesting. It is certain that FSB speed affects performance a lot. When I finish building system, let me compare two system, FSB 40MHz/CPU 160MHz/PCI 40MHz and FSB 50MHz/CPU 150MHz/PCI 25MHz

PC Hoarder Patrol wrote on 2020-03-28, 05:14:

Anonymous Coward wrote on 2020-03-28, 04:47:

I once had one of these boards, but it was dead and I couldn't get it working. I am pretty sure the manufacturer's name was Sunnyvale Labs, but I can't seem to find any information on it. PCchips M921 looks identical, so it was most likely a case of badge engineering.

Thinking of the SYL8884? - this thread mentions it (with links) and the ST1A REV B

TD-4IP-UMC-AIO PCI Socket 3 Motherboard

Indeed it was an SYL8884. The manual is available for it, but strangely it doesn't list the manufactuer's name. I was pretty sure the BIOS on my board had a holographic sticker that said "Sunnyvale Labs" on it, which seems to line up with the SYL in the model number. So even though these look basically identical to M921 they actually have different jumper settings? That's pretty weird. I wonder which one that the OP actually has.

*edit*, ah, I saw ST1A on the poster's board. So are these yet another variant? SYL8884 should have a PS/2 mouse header. I don't see it on this board.