Hi guys,

Recently I got into an unpleasant situation when decided to remove *nix from my oldie netbook ACER Aspire One ZA3 (aka AO751h), updated to the latest BIOS v0.3212 and reinstalled the OEM XP x32, which appeared to reset from ultradma-5 (ata100) down to ultradma-4. As for manual registry tweaking with *DeviceTimingModeAllowed set to '0xfffff', it does help for awhile, the speed increase is quite visual, the device manager reports udma-5, but regularly resets to udma-4...
Indeed, the HDD SMART is 'Good', no udma errs, and replacing doesn't help; moreover, another AO751h behaves the same.

Being a bit naive, I removed 'outdated' XP and installed Windows 7 Starter upgrade bundle--with very pretty the same result! Rather frustrated I booted into *nix and--YES!--udma5 (ata100) instantly and flawlessly at your service. I inquired so-called 'ACER support team', and they kindly replied it's just a BIOS feature... Perhaps, they still cannot tell glitches from features and really must have very many other almost-scientific "answers" like 'This is it', 'It's so, because not the other way', 'Act of God', 'The constellation of the starts', 'It's history', 'Because we really care' and other funny but no good lame excuses.

Obviously, my question is about enabling/forcing udma-5 on the infamous Aspire One for XP or W7, if possible.

TY

Unfortenately, UniATA drivers from alter.org keep crashing at XP boot...

Only *it! An Intel specialist referred me to infoDear my, how come that proprietary hi-teky leading vendors can't do properly what open source can?! It seems to be but an artificial (marketing) limitation, because even udma-6 turns on for awhile.

Case closed, installing *nix.