SAS and SATA are using the same power and data slot. SAS HDD cannot be detected if you plug the SATA cable, but SATA can be detected fine when you plug SAS cable. I haven’t put any though about it until when I installed database on the SATA drive that was plugged to SAS cable. when I imported the data to the database it took all night long to finish then what normally only 30 minutes.
So then I checked the server performance using performance monitor, there I saw disk queue waiting time had reached the roof. so to get the detail I added another parameter on individual physical drive, then I saw that the SATA drive had very low performance. So I installed HDD diagnostic utility HDD sentinel since it is freeware. There I saw that the read/write was so slow, only in 10’s kilo bytes.
After days tweaking from bios, to the system and hadn’t been able to made a differences, I took off the casing side and looked inside and something hit my head, why should I use the SAS cable? So I took it off and use the regular SATA cable and restarted the server, reimporting my database and it even faster than the regular 30 minutes I took using SAS drive…
dunno why, SAS should be faster than SATA it is 15000 rpm twice the SATA 7500 rpm.
Anyway, since it is better now I refuse to inquiry further, hehehe… let sleeping dog lie.