I found the reason.

來源: 於 2004-12-28 15:07:42 [舊帖] [給我悄悄話] 本文已被閱讀：次

I found the reason. I need to enable the DMA on the IDE bus. After doing that, I got 4-6x writing speed now.
But I still have the compatibility issue.
By the way, the IOMagic Tech help is not good, they don't know the reason, only ask me to download the new firmware which is not helpful at all.