Ok here is what i found out so far:
I have a Sil3512 pci Raid card here. The newest bios is apearently b4384.bin. I have the card in a 440BX Board. And Win98 installed on an ide harddrive.
I put the bios files and the flash program on the ide harddisk and flashed it in MD-Dos mode. He didn't accept the bios file at first but then just flashed it....
As a original raid card its not even possible to install a driver in 98.
As soon as its flashed to the non Raid bios it installs fine.
My plan was to use a ssd with it. So i connected a 120GB Sandisk and tested with Atto Disk 2.2
result about 30mb/sec
then i formatet the ssd on a win 10 computer because i heard this would take care of Alignment issues.
Funny enough it only offers Fat32 for partitions up to about 32GB. So i made such a partition for testing.
after this i connected it back to the 3512 controller.
slightly more performance but not much.
Tested a stanard 160GB sata Notebook harddrive with the contoller. 70MB/sec Read/write speed.
Win98 installs fine on the said notebook drive. Although fomat c: shows it as a 24MB Drive instead of 32GB.
But windows install immediately finds the hard drive as if it is ide connected to the mainboard.
in contrast the ssd brings quite some trouble. windows install finds it and checks it after starting setup. result: "bad sectors". checkdisk offers to correct it but with enter key put down it corrects endless errors for half an hour.
tried another ssd. on this one i cant even write install files (98cab).
does it sound like an alignment problem ? and why is it so slow on atto Disk ?