Motherboards are not very likely to be a problem, but getting the VLB cards play along can be. Neither of my VLB video cards (ET4000W321 and GD5428) work with 0WS at 40MHz bus for example.
Wait states on RAM will be unavoidable, there are no FRM (or EDO) sticks out there than you can run without them and no motherboard offers 0 wait accesses cycles anyway and that's one reason why plenty of cache is important. 50ns modules are likely fastest you can find. For cache you'll want to find some 10ns chips to use.
I'm not sure what chipset will have best perfromance and configurability. Intel ones will have worst memory performance, I'm not sure how SiS, OPTi and UMC stack up (or any other chipset maker).

Tiido wrote:

Motherboards are not very likely to be a problem, but getting the VLB cards play along can be. Neither of my VLB video cards (ET4000W321 and GD5428) work with 0WS at 40MHz bus for example.
Wait states on RAM will be unavoidable, there are no FRM (or EDO) sticks out there than you can run without them and no motherboard offers 0 wait accesses cycles anyway and that's one reason why plenty of cache is important. 50ns modules are likely fastest you can find. For cache you'll want to find some 10ns chips to use.
I'm not sure what chipset will have best perfromance and configurability. Intel ones will have worst memory performance, I'm not sure how SiS, OPTi and UMC stack up (or any other chipset maker).

Okay thanks!
I'm going to edit the question adding the assumption that the installed cards will be able to hold the 40 MHz

I have perfect stable VLB on my machine, using 40mhz FSB, and two VLB cards at 0 wait state. Now... I am running with an DX2-80 and not DX4-120. The last time I used a DX4-120, it would not run with the same VGA card in question, only with PCI, yet that was a different motherboard.

The card's that I am using is an S3-805-VLB (Spea Mirage) and the controller's that I have tried are a Pine-627-IDE and an Buslogic BT-445S VLB SCSI-Controller.

brostenen wrote:

I have perfect stable VLB on my machine, using 40mhz FSB, and two VLB cards at 0 wait state. Now... I am running with an DX2-80 and not DX4-120. The last time I used a DX4-120, it would not run with the same VGA card in question, only with PCI, yet that was a different motherboard.

The card's that I am using is an S3-805-VLB (Spea Mirage) and the controller's that I have tried are a Pine-627-IDE and an Buslogic BT-445S VLB SCSI-Controller.

this is useful! Thanks!!

I wonder why the DX4-120 issue! The bus is exactly the same!!! 😕 😕 weirdnesses of the computer world

I've done my tests on a mb1433 with a tekrzm dc680t disk controller and a tseng labs et4000w32p.

Also tested a hot419 and a 486sv2gx4 with success.

No knowledge of PCI boards except for the MB8433, which runs at 27mhz.

Thanks.
Lol I googled MB1433 and I found this ultrasonic sonar:
https://www.maxbotix.com/Ultrasonic_Sensors/MB1433.htm

So, are you saying that both the MB1433 (whatever it is), the HOT-419, and the 486S2vGX4 work finely at 40 MHz FSB, 40 MHz VLB, and RAM?

Thanks

For Vesa Local Bus maybe try the GA-486VS - I had it running at 50 with 0WS and an AvanceLogic based gfx card.

For PCI maybe try the LuckyStar LS486E - I have it running at 60mhz with a 1:1 - fsb:PCI ratio although I wouldn't recommend it for 24/7 usage. The board seems to have lax timings when it comes to the PCI bus so it is very forgiving in regards to "abnormally" high clockspeeds.

A UMC based board features better speeds when it comes to the PCI bus, so maybe go with something like a GA-486AM/S, Shuttle HOT433 or a Biostar MB-8433-UUD.

If you want to have a PCI based SCSI card running then forget about very high PCI speeds as the card most likely won't work.

amadeus777999 wrote:

For Vesa Local Bus maybe try the GA-486VS - I had it running at 50 with 0WS and an AvanceLogic based gfx card. […]
Show full quote

For Vesa Local Bus maybe try the GA-486VS - I had it running at 50 with 0WS and an AvanceLogic based gfx card.

For PCI maybe try the LuckyStar LS486E - I have it running at 60mhz with a 1:1 - fsb:PCI ratio although I wouldn't recommend it for 24/7 usage. The board seems to have lax timings when it comes to the PCI bus so it is very forgiving in regards to "abnormally" high clockspeeds.

A UMC based board features better speeds when it comes to the PCI bus, so maybe go with something like a GA-486AM/S, Shuttle HOT433 or a Biostar MB-8433-UUD.

If you want to have a PCI based SCSI card running then forget about very high PCI speeds as the card most likely won't work.

Wow such a summary, thanks!

Well, rather than pushing/overclocking bus frequencies very highly, my goal is stability and compatibility at the "odd" 40 MHz frequency.
Because usually motherboards support settings for the classical 25, 33, and 50 MHz, but not 40, sometimes there isn't even a jumper setting for 40 MHz.

The same applies to CPUs: supported almost universally are 33, 50, 66, 75, 100. When it comes to 120, many times there are no settings.

Or, if the motherboards support a 40 MHz FSB, most of the times it forces the PCI bus down to 27 MHz.

So, my ultimate goal is a Motherboard that fully supports the (and is stable at) 40 MHz frequency on everything: FSB, RAM, Cache, and bus slots, whether they are VLB or PCI.

Which of the ones you suggested would qualify?

Thanks so much again!

aries-mu wrote:

Thanks. Lol I googled MB1433 and I found this ultrasonic sonar: https://www.maxbotix.com/Ultrasonic_Sensors/MB1433.htm […]
Show full quote

Thanks.
Lol I googled MB1433 and I found this ultrasonic sonar:
https://www.maxbotix.com/Ultrasonic_Sensors/MB1433.htm

So, are you saying that both the MB1433 (whatever it is), the HOT-419, and the 486S2vGX4 work finely at 40 MHz FSB, 40 MHz VLB, and RAM?

Thanks

biostar mb-1433-uiv-a.
Yes they work well. Even 50mhz.
But I tried did only, not windows.

Both the Shuttle HOT433 and the Gigabyte GA-486 AM/S drive the PCI bus fully or at 50% speed - it's a BIOS setting and can easily be changed(the BIOS for the HOT433 needed an update though).
The LS486E has a jumper(I think it's 19) which is not documented but similarly halves the clock-speed.

Never had a problem with these boards at 40mhz fsb and full PCI speed be it graphics cards or the IDE controller. You only have to get cautios from 50 upwards.

Again, test and experiment yourself.

amadeus777999 wrote:

Both the Shuttle HOT433 and the Gigabyte GA-486 AM/S drive the PCI bus fully or at 50% speed - it's a BIOS setting and can easil […]
Show full quote

Both the Shuttle HOT433 and the Gigabyte GA-486 AM/S drive the PCI bus fully or at 50% speed - it's a BIOS setting and can easily be changed(the BIOS for the HOT433 needed an update though).
The LS486E has a jumper(I think it's 19) which is not documented but similarly halves the clock-speed.

Never had a problem with these boards at 40mhz fsb and full PCI speed be it graphics cards or the IDE controller. You only have to get cautios from 50 upwards.

Again, test and experiment yourself.

sunaiac wrote:

biostar mb-1433-uiv-a. Yes they work well. Even 50mhz. But I tried did only, not windows. […]
Show full quote

aries-mu wrote:

Thanks. Lol I googled MB1433 and I found this ultrasonic sonar: https://www.maxbotix.com/Ultrasonic_Sensors/MB1433.htm […]
Show full quote

Thanks.
Lol I googled MB1433 and I found this ultrasonic sonar:
https://www.maxbotix.com/Ultrasonic_Sensors/MB1433.htm

So, are you saying that both the MB1433 (whatever it is), the HOT-419, and the 486S2vGX4 work finely at 40 MHz FSB, 40 MHz VLB, and RAM?

Thanks

biostar mb-1433-uiv-a.
Yes they work well. Even 50mhz.
But I tried did only, not windows.

Great, thanks guys.

aries-mu wrote:

brostenen wrote:

I have perfect stable VLB on my machine, using 40mhz FSB, and two VLB cards at 0 wait state. Now... I am running with an DX2-80 and not DX4-120. The last time I used a DX4-120, it would not run with the same VGA card in question, only with PCI, yet that was a different motherboard.

The card's that I am using is an S3-805-VLB (Spea Mirage) and the controller's that I have tried are a Pine-627-IDE and an Buslogic BT-445S VLB SCSI-Controller.

this is useful! Thanks!!

I wonder why the DX4-120 issue! The bus is exactly the same!!! 😕 😕 weirdnesses of the computer world

Yeah.... Dont know what and how... Anyway.
The machine that I have 2 VLB cards running in, are the one in this blog post I made some time ago.

https://to9xct.blogspot.com/2018/09/dextor-ta … -build.html?m=1

Yeah I had already snicked in your post this morning 🤣 🤣 beautiful!!!!