I should probably search online, but for the sake of the conversation - there should be testing devices that allow to vary the frequency.
It makes sense to be that way. Do you know ?

I replaced the water pump, thermostat, and 3 related gaskets on my 1979 Benz. It is rolling now, yes.

I would be really surprised if you can run 2-1-1-1 with 512K single-banked cache on this board, even at 40 MHz.

Wasn't an SRAM speed tester supposed to be one of the options added to the UCA? Maybe it didn't get added yet... https://www.cpu-world.com/forum/viewtopic.php?t=29971

1979 Benz - classy.
Around that time I was still walking straight under the table.

I think the UUD board has the chops for it. I was hoping for 60mhz, but looks like I have to be more humble. Let's see ...

This is a great project. Didn't see sram adapter, but still very impressive.

feipoa wrote on 2021-06-27, 06:20:

So you put device=c:\um8673.sys into the config.sys, but what file do you edit to set the speed, e.g. Speed 16, 17, etc ? I assume those speeds are MByte/s values?

Note that I have the MB-8433UUC-A which has the UM8886AF rather than BF, but they seem similar.
One difference is with this board, there is no option to control the PIO mode from the BIOS. There is only UM8673.SYS, as well as a small program I wrote to access the drives directly and switch to PIO mode 4.

The fastest UM8673.SYS speed that works on the system is 15. Any faster and it hangs.

This SPEEDSYS with an 8.4GB IDE drive C:, and a 320GB SATA drive D: attached through an IDE converter. The 320GB drive should be able to saturate this chip and seems to do so. I think it would be hard to get it going much faster. Both the UM8673.SYS as well as the small utility were run for those tests.

In addition. The UMC Win95 driver actually works on my system with OSR2.5. However, performance is slower with it than the built in Windows 95 drivers! My utility to set the speed to 15 and PIO mode to 4 without loading a TSR may help though. In the Roadkil thing on the D: drive I eventually get in the mid 4s MB/s sequential read, after running several trials.

I also tried with a 240GB SATA SSD through the converter. Performance was worse than either mechanical drive. I think it is because it lacked multi-sector transfers aka block mode.

jakethompson1 wrote on 2021-07-14, 06:05:

Note that I have the MB-8433UUC-A which has the UM8886AF rather than BF, but they seem similar.
One difference is with this board, there is no option to control the PIO mode from the BIOS. There is only UM8673.SYS, as well as a small program I wrote to access the drives directly and switch to PIO mode 4.

Yes, it is not the best setup. I am going to give your utility another spin soon.
The UMC DOS IDE driver hangs hard at 180MHz, so wonder if your codepath can be used as a workaround.

The chipset and the overall implementation of this motherboard are pretty good, but the IDE controller is mediocre at best.
This is where third party PCI UltraATA/RAID controllers come into play, but unfortunately i was not able to make any of that work on NT4.
Promise, SiS and 3ware, etc.
So for complete compatibility - back to the basics.

jakethompson1 wrote on 2021-07-14, 06:05:

The fastest UM8673.SYS speed that works on the system is 15. Any faster and it hangs.

Initially i had it at speed 10, but recently was able to go all the way up to 17 and still fine - as far as i can tell.
Still, it does not break over 10Mb/s in Speedsys, despite running the system at 180MHz 3x60.

For comparison - here is how VLI + DX5@160 + Promise EIDE2300 Plus looks like.
A whole different story ...

jakethompson1 wrote on 2021-07-14, 06:05:

This SPEEDSYS with an 8.4GB IDE drive C:, and a 320GB SATA drive D: attached through an IDE converter. The 320GB drive should be able to saturate this chip and seems to do so. I think it would be hard to get it going much faster. Both the UM8673.SYS as well as the small utility were run for those tests.

In addition. The UMC Win95 driver actually works on my system with OSR2.5. However, performance is slower with it than the built in Windows 95 drivers! My utility to set the speed to 15 and PIO mode to 4 without loading a TSR may help though. In the Roadkil thing on the D: drive I eventually get in the mid 4s MB/s sequential read, after running several trials.

I also tried with a 240GB SATA SSD through the converter. Performance was worse than either mechanical drive. I think it is because it lacked multi-sector transfers aka block mode.

Good info. My observations are similar.

As a side note - i find HDD/SSD impractical for retro computing, compared to CF cards.
Reimaging, moving bits around is so much easier with CF cards = saved time.

In continuation to the 486 at 180MHz - an exercise in practicality:

LuckyStar LS-486E rev:D

Highly integrated, cost reduced and even more compact version of the previous rev:C2 PCB.
2 RAM slots only, soldered on board 256Kb 15ns L2 cache chips.
Late UMC BIOS that speaks EDO and is different than the BIOSes in the previous board models that don't like EDO.
Had to solder a third jumper to enable the full set of frequencies supported by the clock generator.

Initially all BIOS settings were on MAX and the DOS tests were fine, but then Windows and sensitive 3D Rendering required making a step back.
At the end the system was fully stable with all BIOS parameters set to their optimum performance values, except:
L2 CACHE/DRAM CYCLE WS = 3 (best is 2) <- it will be interesting to see if the C2 version of the board can improve on this with better L2 cache chips
DRAM RAS TO MA DELAY = 2 (best is 1)
DRAM SPEED = Faster (best is Fastest)
HIDDEN REFRESH = Disabled
At 160MHz these settings can be set to their optimum value for even better relative clock-to-clock performance.
Setting the L2 cache in WT mode results in same or better performance, depends on which test you ask. So it was used that way.

Here is what SpeedSys reported:

And the standard set of tests below.
Gray bar in the Quake 1 test indicates all BIOS settings on MAX - stable in DOS - not bad, not bad.
Numbers are achieved by using a mixture of Matrox Millennium and Permedia 2 PCI video cards in DOS and Matrox Millennium for the Windows test.
Compared against Biostar UUD rev:2 @180MHz and Asus PVI / VLI boards @160MH.

If i feed 12V to the Peltier element (up from the 5V used atm for the "practical" aspect of the 180MHz exercise) then surprisingly i can set some of the listed above BIOS settings to their optimal values and get even better performance without compromising complete stability. Not sure why better CPU temperature conditions affect seemingly unrelated components of the system.
But i will leave this for a round of "impractical" overclocking at some point later. Anyhow ...

Back to the point - this is an impressive motherboard - fast and stable. It can be faster than Biostar UUD @180MHz, but at the expense of some stability issues. Completelly stable system is slower than UUD, mostly attributed to the hardcoded L2 cache situation.
Also, it is very simple to operate - no L2 jumpers given the soldered chips, CPU config jumpers closely packed in one place with few configurations, that are easy to follow.
It will be interesting to see if the C2 version can outdo this D variant ...