pshipkov wrote on 2021-06-21, 07:16:
But what you are after here ?!
I am starting to wonder if there is a large dependency on the PCI frequency. I am also starting to wonder if the UMC driver has issues with Cyrix 5x86 CPUs.
You are running your ISA bus at PCICLK/2, so 20 MHz. Why? I am unable to run mine that high when the FSB is at 66 MHz. I must set my PCI bus to 33.33 MHz for the system to boot. But I did do some testing with the ISA divisor. With the ISA clock at 8.33 MHz, the Speedsys buffered read score is 4750 KB/s. With the ISA clock at 11.11 MHz, the score is 4800 KB/s. With the ISA clock at 16.7 MHz, the score is 4850 KB/s. Small, but the dependency is there. I bet the PCI dependency is even more extreme.
Also, my L2 wait states are at 3-2-2-2 due to the FSB setting.
With ATTO, looks like your average max speed is around 6000 KB/s. It is odd to have an outlier at 9000 KB/s for 2048 KB block size. Why is this happening?
Does your SanDisk Ultra support multi-sector transfers?
Yes, could you please share your HDD BIOS setup screen? I put a 32 GB SanDisk Extreme Pro 32 MB UDMA7 card in the system and I get really odd values when I autodetect HDD, e.g. disk size is something silly like "P014". Did you find the newer SanDisk cards to not work as well?
For the UMC driver, are you using v3.1 for DOS and v3.2 for Windows? The ATTO Windows benchmarks with the UMC driver are peculiar. I don't normally see the speeds bouncing around like that and I recently HDD benched about a dozen of my systems.
I assume you using the 5V setting on your CF-IDE adapter and not the "power-over-IDE" jumper for 3.3V? Does the IDE port on this MB even supply 3.3V to IDE header (I think pin 20)? I can't imagine it would.
You mentioned that the standard windows driver doesn't have the DMA option persist, but is there such an option with the UMC driver? How are you getting 23000 KB/s? PIO-4 doesn't even support that kind of speed. Would you be willing to take a stop watch measure the real-world bandwidth with some, say, 200 MB files? Ideally, you'd want to go from something with UltraDMA speeds onto the CF card, and from the CF card back to the UDMA controller. Then try from Primary IDE to Secondary IDE. Record the values. I'll do the same on my system and we can compare the results.
I think it is going to take quite some time to figure out exactly what is going on here.
I transferred two files of type mpg, with sizes 29,699 KB and 132,617 KB.
From Promise UDMA100 PCI card to IDE PIO-4 = 2750 KB/s and 2822 KB/s -------> average = 2786 Kbyte/s
From IDE PIO-4 to Promise UDMA100 PCI = 2475 KB/s and 2550 KB/s ------> average = 2512 Kbyte/s
Notice how these results aren't even close to the 4,000 KB/s reported by ATTO for a 8,192 KB block size