A 24TB volume on a Mac Pro

This is by far the largest RAID I’ve ever created: 24TB as twelve (12) 2TB Hitachi 7K2000 drives. Not an idle exercise, my goal was extreme testing of my IntegrityChecker program, as well as to beat up on two of the FirmTek SeriTek/2ME4-E eSATA cards. It’s looking like the SeriTek/2ME4-E will be my new recommended eSATA card: it has run extremely well and it works perfectly booting into the 64-bit Snow Leopard kernel.

Unfortunately, while this RAID 0 stripe can achieve over 1400MB/sec speed, the quad-core Mac Pro Nehalem 2.66GHz maxes out its CPUs at about 1125MB/sec (using IntegrityChecker). Of course, that’s of purely academic interest, since there’s nothing you can do that requires this kind of disk speed. Well, perhaps 4K uncompressed video.

Four of the 2TB drives are in the Mac Pro internal drive bays, and the other eight are in two FirmTek SeriTek/2eEN4 enclosures hooked up to two SeriTek/2ME4-E eSATA cards.

disktester run-area-test -c 128M -t 4G -i 3 h12
...
--- Averages for "h12" (4GB/128MB, 3 iterations) ---
Area (21.8TB)    Write MB/sec    Read MB/sec
      0%            1475            1451
     10%            1347            1381
     20%            1378            1359
     30%            1219            1290
     40%            1249            1211
     50%            1231            1200
     60%            1181            1135
     70%            1096            1038
     80%             970             954
     90%             905             855
    100%             756             716
Average write speed across the volume: 1164MB/sec
Average read speed across the volume: 1145MB/sec