" Just installed a 2.66GHz Xeon Quad Xserve with a 15,000 RPM Disk (SAS) (They are just now shipping). This is our 12th Xserve. We have 5 Xserve Raids also. This unit also has a 7200 RPM disk in another bay.
I ran Xbench (1.3) disk benchmarks with the following results:

ST3808110AS (7200rpm) versus ST373455555 (15,000rpm)
(Single Drive compared to Single Drive)
(Note: I asked him if both drives were empty (as drives get slower as they fill up) and he said the 15,000rpm drive is 1/2 full. the 7,200 RPM drive was empty. Just a FYI.-Mike)

Sequential:
Uncached write (4K) 138.59 vs. 239.19
Uncached write (256K) 126.24 vs. 218.20
Unchached Read (4K) 100.64 vs. 101.61
Uncached Read (256K) 142.38 vs. 247.39

Random: (MB/sec)
Uncached write (4K) 14.20 vs. 27.99
Uncached write (256K) 101.88 vs. 307.66
Uncached read (4K) 93.34 vs. 205.29
Uncached read (256K) 140.17 vs. 291.50

Regards, Steve "

I asked Steve if he could run the AJA System Test Benchmark on the drives.

" 3 Screenshots regarding AJA Kona tests;
1.) 15,000 RPM Drive ("Speed Demon") with system cache enabled
2.) 15,000 RPM Drive ("Speed Demon") with system cache disabled
4.) 7,200 RPM Drive ("Xeon1") with system cache disabled
5.) For reference; and Xserve Raid (Raid Level 5 volume (6 drives) though a Fibre Optic Switch) with system cache disabled

NOTE: The 4 core Xeon Xserve has some active programs on it today but I feel they probably did not harm the test (LDAP Replica; Radius Replica; Net Boot, and a few other things)
(Reminder I asked him about the status of the drives (blank/empty drives are faster, speeds take a nose drive as they fill up (outer tracks fastest), get fragmented-Mike)
The 15,000 RPM drive is 1/2 full; the Xserve Raid is about 1/2 full but is really fragmented now, the 7,200 RPM (Xeon1) drive is empty.

The SAS drives show real potential. You can't imagine how much faster OSX Server appears to run with this drive as a boot device. Quite nice. Merry Christmas to you.
Regards, Steve"

15,000RPM Drive (appx. 50% Full) with system cache enabled

15,000RPM Drive (appx 50% Full) with system cache disabled

7,200RPM Drive (Empty) with system cache disabled

Xserve Raid 5 volume (6 drives) though a Fibre Optic Switch (system cache disabled)
(Volume appx 50% full and fragmented)