硬盘的故事还没完

拿到新硬盘后，把它设置为master，赶紧在上面装了一个操作系统，并把旧硬盘设置为slave。这样从新硬盘启动系统后把旧硬盘的数据拷贝到新硬盘上。拷贝数据时明显觉得拷贝速度很慢。复制一个2，3G的文件夹要半个多小时。这对两个带有8M cache的ATA 133硬盘来说简直太慢了。当时我想估计是就硬盘有问题，读取数据比较慢。也就没有太在意。心里还想，只要数据能读出来就不错。经过漫长的数据复制之后，我把旧硬盘卸下来，电脑里仅剩一个硬盘，运行起来感觉很不对劲。光启动就比以前满了好多，winxp 那个滚动条要走近30下才能启动起来。登陆进入后打开一个资源管理器也有明显的迟钝等待。1个G的内存和250 G的硬盘不应如此慢啊？！
又去查看日志，几个连续的红色由ATAPI引起的错误引起了我的注意:

Ereignistyp: Fehler
Ereignisquelle: atapi
Ereigniskategorie: Keine
Ereigniskennung: 9
Datum: 09.02.2006
Zeit: 12:36:34
Benutzer: Nicht zutreffend
Computer: SWHTH1053
Beschreibung:
Das Gerät DeviceIdeIdePort2 hat innerhalb der Fehlerwartezeit nicht geantwortet.

Weitere Informationen über die Hilfe- und Supportdienste erhalten Sie unter http://go.microsoft.com/fwlink/events.asp.
Daten:
0000: 0f 00 50 00 01 00 a4 00 ..P...¤.
0008: 00 00 00 00 09 00 04 c0 .......À
0010: 00 01 00 00 00 00 00 00 ........
0018: 00 00 00 00 00 00 00 00 ........
0020: 00 00 00 00 00 00 00 00 ........
0028: 00 00 00 00 00 00 00 00 ........
0030: 00 00 00 00 07 00 00 00 ........
0038: 40 00 00 0e 00 00 00 00 @.......
0040: 00 20 0a 12 40 03 20 40 . ..@. @
0048: 00 80 00 00 0a 00 00 00 .€......
0050: 00 00 00 00 38 6b 37 86 ....8k7†
0058: 00 00 00 00 70 9e 36 86 ....pž6†
0060: 02 00 00 00 17 77 66 00 .....wf.
0068: 28 00 00 66 77 17 00 00 (..fw...
0070: 40 00 00 00 00 00 00 00 @.......

刚好连续6次错误！

上google一查找到这个链接：
http://support.microsoft.com/?scid=817472

一读才知道，造成该问题的原因是：
After the Windows IDE/ATAPI Port driver (Atapi.sys) receives a
cumulative total of six time-out or cyclical redundancy check (CRC)
errors, the driver reduces the communications speed (the transfer mode)
from the highest Direct Memory Access (DMA) mode to lower DMA modes in
steps. If the driver continues to receive time-out or CRC errors, the
driver eventually reduces the transfer mode to the slowest mode (PIO
mode).

原来我的新硬盘才从旧硬盘拷贝数据时由于遇到多次（连续6）超时错误，把读取模式从Ultra DMA改为了速度很慢的PIO-Modus。上文提供了解决办法，卸载硬盘的驱动atapi.sys，然后重新启动电脑，系统会自动识别安装正确的驱动。

针对win xp pro的详细方法如下：
To re-enable the typical, or faster, transfer mode for an affected device:

1.	Double-click Administrative Tools, and then click Computer Management.
2.	Click System Tools, and then click Device Manager.
3.	Expand the IDE ATA/ATAPI Controllers node.
4.	Double-click the controller for which you want to restore the typical DMA transfer mode.
5.	Click the Driver tab.
6.	Click Uninstall.
7.	When the process completes, restart your computer. When Windows restarts, the hard disk controller is re-enumerated and the transfer mode is reset to the default value for each device that is connected to the controller.