@Lylat1an
@cyclone3d always gives good advice. For a good DOS retro gaming experience, it's better to have systems with ISA slots, limiting to motherboard with Slot 1/Slot A. Socket 370 can do, but often have only one ISA slot. Using an adapter IDE <> SATA works very well. From my experience, the only thing is that sometimes, a few SATA drives can be a little long to be detected during POST. There is also the possibility to use controllers such as Promise controllers and the like that can bypass BIOS limits that exists in older machines, there is ISA and PCI models. PCI IDE or SATA controllers (with or without RAID support) but with embedded BIOS so it can boot can do too with the advantage of SATA versions requiring no adapter in your case.
Just for information, can you tell us what is your SATA controller card?
Edit: But if your target is W9x gaming especially, CPU speed is not a problem and ISA slot nor required. Correctly programmed DirectX games will just work fine providing the fact your drivers are compatible.
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