>> New models of IBM IDE drives are fast enough to consume a significant >> fraction (perhaps > 100%) of PIO mode 4 bandwidth (16.6 MB/s). Don't >> use them without DMA. Don't use them without UltraDMA (33.3 MB/s) if >> you want full performance. > >I presume the last "don't" should have been a 'do', i.e. _do_ use them >with UltraDMA if you want full performance...?
Don't use without == do use with. >Also, the controller their running off isn't _Any_ DMA capable, at a guess >it's going to be PIO4 tops, in which case (and as EIDA/UltraDMA are mean't >to be 'backwards' compatible) - does this point to a bug/problem with the >wdc driver? (i.e. drive too fast = wdc interrupt timeouts?) This is a general problem with i/o capabilties exceeding system capabilities. Bruce To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-current" in the body of the message
