[lkml]   [2001]   [Jan]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [preview] Latest AMD & VIA IDE drivers with UDMA100 support
On Sat, 20 Jan 2001 14:57:07 -0800 (PST), Andre Hedrick wrote:

>Vojtech, I worry that the dynamic timing that you are calculating could
>bite you. Timings are exact especially at modes 3/4/5 the margins go to
>an effective zero for varition or wiggle room. The state diagrams from
>Quantum that created the Ultra DMA 0,1,2,3,4,5 show how darn tight it
>constrained. You need to assume absolutes because the various board
>makers screw up the skew tables by the PCB lane traces.

I am not sure this is just a question of small variations. The hdparm
-t differences between these two versions is quite significant. This
evidence would imply that the two approaches are making fundemental
different decisions about what my hardware can do!

Under 2.2.17

Timing buffered disk reads: 64 MB in 21.86 seconds = 2.93 MB/sec

Timing buffered disk reads: 64 MB in 20.81 seconds = 3.08 MB/sec

Under 2.4.0

Timing buffered disk reads: 64 MB in 6.58 seconds = 9.73 MB/sec

Timing buffered disk reads: 64 MB in 6.59 seconds = 9.71 MB/sec

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:08    [W:0.260 / U:0.560 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site