_UV_ wrote on 2021-04-04, 22:45:
bloodem that is definitely not a BIOS issue, that is HDDs newer than UDMA33 (most of them) working properly only at their native UDMA 66/100 or PIO. That is true for Seagate and IBM drives.
That's also half of famous W98 shutdown bug. Because of that many people suggest using third party controllers.
that's an interesting statement, but if it such a general issue backwards compatibility issue on IDE existed, wouldn't it be much more widely known as UDMA66 became a thing in 1998/99 and these drives would have been widely used on UDMA33 connectors? or did nobody bother to tick that DMA checkbox?
moreover i looked up the manual for that ST380021A drive you mentioned and it literally lists UDMA 0-5 modes as supported. and as another example, both drive types from seagate and WD used in the original xbox were UDMA100 drives that were connected with a 40-wire cable... unfortunately i can't find any good info on whether the xbox OS actually used UDMA33 or PIO.
also, it's worth saying that 3rd party IDE controllers aren't necessarily a magic bullet either. i've once made a post about issues with silicon image and promise controllers and i think there's other threads about that as well. all in all i find SCSI actually less troublesome as you'd never even have to think about these issues there, and quality controllers are available for basically nothing... it's a shame that the drives do tend to be louder for whatever reason.