Sata II is it backwards compatable with SATA I

[JEPM]

I want to upgrade my DELL Inspiron 9400 with a bigger hard drive and Windows 7. I asked DELL and they say I can only have a SATA drive 2.5" 160GB disk maximum. I can find SATA drives of 160GB 2.5"s but they are SATA II interfaces.
My question is "are the new SATA II drives compatable with my SATA I (I assume) disk controller on the mother board".
Look forward to clarification on this if you can help.
Thanks
John

 

[Paperdoc]

The usual answer is yes - in fact, there is not supposed to be any question here. The design of SATA systems makes a HDD and its controller communicate and negotiate what communication speed they will use, so that a SATA II HDD SHOULD simply agree to operate at the slower communication speed of the SATA I controller. However, there have been systems that fail to do this. For that reason, many HDD makers provide a way to force a SATA II HDD to operate at the slower speed at all times. On 3½" desktop units, WD, Seagate and several others had you install a single jumper on pins on the back edge of the drive to force this. (This method is just like the jumper setting process on older IDE drives. With this single exception, there are NO other jumper settings that anyone should change on a SATA drive.) Some other makers used software switches set using a free utility you download from their website. I do NOT know how this is done in the 2½" drives used in laptops, so check exactly how you can force the new drive you plan to buy back to SATA I speeds just in case it is necessary. As I said, you are not supposed to have to do this manually, but sometimes it is necessary.

 

[JEPM]

The usual answer is yes - in fact, there is not supposed to be any question here. The design of SATA systems makes a HDD and its controller communicate and negotiate what communication speed they will use, so that a SATA II HDD SHOULD simply agree to operate at the slower communication speed of the SATA I controller. However, there have been systems that fail to do this. For that reason, many HDD makers provide a way to force a SATA II HDD to operate at the slower speed at all times. On 3½" desktop units, WD, Seagate and several others had you install a single jumper on pins on the back edge of the drive to force this. (This method is just like the jumper setting process on older IDE drives. With this single exception, there are NO other jumper settings that anyone should change on a SATA drive.) Some other makers used software switches set using a free utility you download from their website. I do NOT know how this is done in the 2½" drives used in laptops, so check exactly how you can force the new drive you plan to buy back to SATA I speeds just in case it is necessary. As I said, you are not supposed to have to do this manually, but sometimes it is necessary.

Thank you Paperdoc for such a detailed and quick responce. I'll take your advice and be very wary about which drive I buy. I've been checking out a SAMSUNG 160GB 2.5" SATA II 5400RPM 8MB drive. Am awaiting on a definitive answer to the speed switch question now.
Thanks again
JEPM

 

[JEPM]

Best answer selected by JEPM.