Which chipsets support hot-UNplugging of SATA II HDDs under Win XP?


Jul 30, 2007

I am from Moscow, Russia. I would like to ask a couple of questions, if I may, since I’m desperately trying to get the answers to my questions at Russian forums.

It is known that hot-plugging for SATA II hard drives has been realized in south bridges ICH7 and ICH9 (with the indexes R, DH, DO). With the AHCI driver installed for Windows XP hot-plugging is stabile and as it should be.
In Intel documentation for the chipsets, for motherboards and for the company utility Matrix Storage there is no word about hot-unplugging.
I am interested in the answers to my following questions:
1. Has hot unplugging of hard drives been realized in ICH7 and 9 controllers under Windows XP control and how secure is the hot-unplugging? Could be the hard drive turned safely off by clicking the icon of HDD in the System Tray?
2. Does the operation of AHCI as a whole and hot-unplugging particularly differ in ICH9 and ICH7?
3. Would it be possible to stop and then to start spindle of a hard drive under Windows XP control with standard means of the controller and BIOS?

My questions are caused by the following thoughts. If several hard drives are used in a personal computer and some of them are used exceptionally for the information storage, to lower the risks of loss of their content and decrease the hard drive noise it would be not a bad solution to organize secure hot plugging/unplugging of these hard drives. By that to insure maximum reliability it would be useful to stop the disc spindle after hot unplugging and start it before the hot plugging.
Of course, external UBS hard drives could be used to realize hot plugging and Mobile racks for the disc power shut down and Windows Device Manager for hard drives logical disable/enable as well. However, I want to solve the problem with the hot-unplugging function. And here is why.
External USB discs are no good since it is quite expensive, you need some space for several discs storage, new wires appear, and the most important is the lower speed compared with SATA II. The problem could be partially solved with the use of internal USB discs, but as I know they are not produced. As far as the Mobile racks use they do not insure discs safe hot unplugging (at least mass models) since they could be used for my purposes only as a button for power turn off of the hard disc. If the complete power shut down is not required and only the disc spindle needs to be stopped you could manage it with hdparm program with the -s key (or with the standard means of the controller, if they are available). Especially I am planning to assemble a quiet computer and place all discs in boxes of Scythe Quiet Drive type, whereas Mobile racks does not substantially decrease the noise of the hard drives.
Windows Device Manager does not allow to securely turn off the disc. If you turn off the hard disc and at this moment the operational system all over sudden addresses to the disc then the computer may hang or partial loss of the information on the hard drive may occur.
So the only possibility for me is to insure the hot-unplugging of several internal SATA II discs in my computer.
New Intel motherboards oriented on mass market appeared now where a set of x35 chipset and Southbridge ICH9 (R, DH, DO) are used. For example DP35DP motherboard. Such motherboards are relatively inexpensive and at the same time they are quite reliable. On the other hand the price for old motherboards on the basis of i975 chipset with Southbridge ICH7 (R, DH, DO) is still quite expensive. For example the D975XBX2 and S975XBX2 motherboard.
Couldn’t be such price difference explained by the fact that the old controller ICH7 (R, DH, DO) ensured higher reliability in operation of AHCI, easier AHCI driver installation for Windows XP or broader hard discs controlling functions?
At this point in time I decided to stop my selection on Intel motherboard and I want to assemble a reliable PC (of course I will not overclock my PC). That’s why I select between D975XBX2 and DP35DP since I need Intel motherboard with ATX form-factor which has COM-port and which doesn’t have incorporated graphics. I cannot come to a solution which of the motherboards between the two to pick up. I have doubts particularly on hot-unplugging (if such function is possible at all) of these motherboards and functional features of AHCL operation.

I would appreciate any of your replies.