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发表于 2005-3-1 09:18:30
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显示全部楼层
[root@localhost root]# hdparm -d0 /dev/hdc
/dev/hdc:
setting using_dma to 0 (off)
using_dma = 0 (off)
[root@localhost root]# hdparm -Tt /dev/hdc
/dev/hdc:
Timing buffer-cache reads: 924 MB in 2.00 seconds = 462.00 MB/sec
Timing buffered disk reads: 14 MB in 3.15 seconds = 4.44 MB/sec
[root@localhost root]# hdparm -d1 -X68 -c3 -m16 /dev/hdc
/dev/hdc:
setting 32-bit IO_support flag to 3
setting multcount to 16
setting using_dma to 1 (on)
setting xfermode to 68 (UltraDMA mode4)
multcount = 16 (on)
IO_support = 3 (32-bit w/sync)
using_dma = 1 (on)
[root@localhost root]# hdparm -Tt /dev/hdc
/dev/hdc:
Timing buffer-cache reads: 928 MB in 2.00 seconds = 464.00 MB/sec
Timing buffered disk reads: 150 MB in 3.00 seconds = 50.00 MB/sec
[root@localhost root]# hdparm -d0 /dev/hdc
/dev/hdc:
setting using_dma to 0 (off)
using_dma = 0 (off)
这是我开启DMA的全部过程及测试,不知道是回事,总不能开机自动开启DMA。
后来打开DMA后,再用[root@localhost root]# hdparm -d0 /dev/hdc,发现竟然还是显示off,速度快是不假,怎么回事?晕死人了! |
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