如何测试软件RAID速度？

Question

OS Debian 6.0.1 amd64

WD1003FBYX * 3
组建软件RAID 5
3个硬盘的分区完全一样，然后
sda1,sdb1,sdc1组成md0
sda2,sdb2,sdc2组成md1...
然后在md0，md1上挂载目录(是叫目录吧？？)

安装完，用hdparm测试速度

1. root@debian:~# hdparm -tT /dev/sda
3. /dev/sda:
4. Timing cached reads:   15994 MB in  2.00 seconds = 8006.80 MB/sec
5. Timing buffered disk reads: 382 MB in  3.00 seconds = 127.28 MB/sec
7. root@debian:~# hdparm -tT /dev/md0
9. /dev/md0:
10. Timing cached reads:   15798 MB in  2.00 seconds = 7908.78 MB/sec
11. Timing buffered disk reads: 392 MB in  3.02 seconds = 129.89 MB/sec

复制代码速度一样？？我这样测试RAID不对吗？？
在WINDOWS上测试时读取速度是相差近一倍的哦...