Raid 10 vs 15K SAS

I am going to upgrade my Transaction Processing Server (still running Window 2000 Server OS). It has extensive Read/Write operations from time to time. R/W performance (especially the write) is my top priority while reliability is the second priority (as I will still carry out scheduled backup daily). I do not know which would be the best configuration :

Raid 10 using 4 SATA II 3.0Gb/sec HD (Intel Server board has onboard Raid 0, 1, 5, & 10) OR
a single 15K SAS HD

Please kindly give me some advise

Thanks a lot.

If you're not concerned with reliability, I think 4 drives in raid 0 would be the fastest for overall bandwidth. If you're doing a lot of small read/writes, though, the 15k drive would be better.

Thanks for all the useful advises. I studied the benchmarks charts in Tom's Hardware. The IO Meter File Server benchmark of a single SAS drive (Seagate Cheetah 15K.5) is way out perform any RAID configuration:

Cheetach 15K.5 SAS HDD == 2075.03
RAID 0 (4 drives) == 960.18
RAID 10 (4 drives) == 812.23

For the sequential read and write, the RAID is better though:

Cheetach 15K.5 SAS HDD == 107.80 (Ave Read Transfer) / 104.70 (Ave Write Transfer)
RAID 0 (4 drives) == 302.20 (Ave Read Transfer) / 273.30 (Ave Write Transfer)
RAID 10 (4 drives) == 153.60 (Ave Read Transfer) / 154.80 (Ave Write Transfer)

However, for a more meaningful comparison, I want to know what kind of hard drives are being used in these RAID configuration for these benchmark tests. I looked around but there was no description for the hardware configuaration under the RAID Matrix Charts. Does anyone has the answers?

Thanks again.

True, but even the latest SATA won't come close to matching a Cheetah for IO.