Thanks to kmahan (and others?) for the new BSP with ATA support!!!
As described in the known issues, DMA isn't working for this port, and transfers are MODE 4 PIO, which results in pretty poor performance (see below).
It is noted that DMA will be supported in a future release. The project I'm working on (custom board) will be transferring image data from an ATA drive, so I'd like to get the best performance possible.
1) Is "hdparm -t" reasonably accurate in reporting performance?
2) What kind of increase might we expect when DMA MODE 5 is supported?
Thanks again for getting this working!
/mnt # hdparm -T /dev/sda
Timing buffer-cache reads: 128 MB in 8.07 seconds = 15.86 MB/sec
/mnt # hdparm -t /dev/sda
Timing buffered disk reads: 64 MB in 21.33 seconds = 3.00 MB/sec
/mnt # hdparm -t /dev/sda1
Timing buffered disk reads: 64 MB in 35.02 seconds = 1.83 MB/sec
/mnt # hdparm -T /dev/sda1
My PC Core-Duo2 Fedora8 system (I know, not really comparable - running SATA-300, UDMA with much more memory, >20x CPU performance) - but for reference:
Timing buffered disk reads: 164 MB in 3.03 seconds = 54.16 MB/sec
Timing buffered disk reads: 230 MB in 3.02 seconds = 76.12 MB/sec