RAID Cluster Size

Blast from the past: originally published in 2003. Testing RAID cards is a long and arduous process. The most difficult part was deciding on a standard cluster size for all cards. While the Promise cards can have from 8k to 2048k, Adaptec’s limit is 128k, and 3ware’s is 64k. All cards default to 64k cluster size, so who am I to argue? Just for comparison sake, I ran the Promise FastTrak100 with three cluster sizes to see the difference.

Blast from the past: originally published in 2003.

Testing RAID cards is a long and arduous process. The most difficult part was deciding on a standard cluster size for all cards. While the Promise cards can have from 8k to 2048k, Adaptec’s limit is 128k, and 3ware’s is 64k. All cards default to 64k cluster size, so who am I to argue? Just for comparison sake, I ran the [intlink id=”115″ type=”post”]Promise FastTrak100[/intlink] with three cluster sizes to see the difference.

AdapterWinBench 99IO MeterHD Tach
HighFileWork-Data-ReadReadWriteCPU
Drive ConfigurationClusterBusinessEndServerStationBaseBurstAverageAverage%
RAID 0 Two Disk85220612099.2989.1277.1375.357273.82426.25.1
64627010400103.99121.79113.9169.535164.628952.111.4
512625017400104.21121.14109.9974.724572.128384.89.3
RAID 0 Four Disk83960397084.9593.3295.5863.651357.31429.44.4
6460009300103.25120.88117.2568.621714.630492.98.8
512704019200108.23126.71123.9474.521338.729240.38.3
RAID 0+1 Four Disk83960397074.1168.7161.9163.651357.31429.44.4
644680396087.84105.6395.7667.931950.11238.82.9
5124770363094.75113.85101.6765.723630.11245.02.8

I’ve indicated best scores in a range with Bold face. I can’t account for the poor write scores with HDTach, although they were quoted in the December issue of Maximum PC as indicating their benchmark is not designed for RAID systems. All tests were run using the Test Platform.

On the two disk system 64k appears to be the clear winner. With four disks, 512k kills with RAID 0 and does well again with RAID 0+1.