UDMA66 mode

What is UDMA66 mode and why does microsoft disable is by default?

Thanks in advance.

 

>> What is UDMA66 mode and why does microsoft disable is by default? <<

This option is disabled by default in all Microsoft Windows Server 2003 SP 1, Windows XP and 2000 releases, no matter what (Intel platform) controller/chipset users' have. In the MSKB Article ID: 247951 Microsoft explains how to "enable support" for it but does not explain why exactly they disable it in the first place...

To find the MSKB Article about it, Google the exact terms:
How to enable UDMA66 mode on Intel chipsets
(and then choose the first search result!) ​

NOTE: Even if you actually have a computer with an Intel chipset that supports UDMA66, you will still find that UDMA66 mode is disabled by default on Windows XP and 2000 computers. And even when DMA is actually "enabled" on IDE channels, by default UDMA/66 mode is still always disabled.

Supposedly, users can improve disc performance by "enabling" it; using a fairly simple regedit.

Good Luck!