I haven't analyzed the driver (unlike the UM8886) but here are some hints from the datasheet:
https://bitsavers.org/components/sis/SiS_85C4 … -497_199507.pdf (PDF p. 41, pp. 128-129, 131-134)

Looks like the settings involve enabling or disabling the write buffer and prefetch buffer, address setup time, recovery time, active time

Your BIOS may already program some of these settings, but it's likely the DOS/Windows driver is more fine grained.
The wdctrl IDE driver that ships with Windows 3.x does not attempt 32-bit I/O and doesn't support any geometry translation, so that could be part of the Windows driver as well.

You might try speedsys to compare speeds with and without the DOS driver.

Are there perhaps people who have installed this driver and can tell us what it does under DOS and Windows 3.11?

I have installed the driver, but unfortunately the PC freezes after loading the driver. He puts my Trancent SATA SSD 30GB with converter from IDE to SATA neatly in Pio 4 mode and says that it has been successfully loaded. It is the first thing he loads from the config.sys and immediately crashes in DOS 6.22. Does anyone know what I can do about this? Could this possibly be because the driver cannot handle my 30GB SSD properly? Without the driver, the PC works fine on this SSD and this mother