SATA II and SAS RAID CARD ROUNDUP

RAID-5 Summary

RAID-5, our good old friend with distributed parity, we're back.  In the past, RAID-5 controllers are very expensive due to the real-time processing power required to calculate and distribute parity among very fast hard drives.  Nowadays, some controllers can do it in software while others have on-board processors faster than many millions of PCs in other parts of the planet.  RAID-5 allows the array to lose one member and still retain functionality.  That failed HDD can be hot-swapped, and its contents be filled up through recalculation of data based on the remaining array members, all in real time. 

Some of these controllers feature RAID-5E or 5EE.  That "E" means one distributed spare drive.  Check Wikipedia for a more complete explanation - I did, but wish not to cut and paste here.  But for our purposes, we'll focus on plain old RAID-5.

HD Tach RW v3.0.1.0, 8MB Zones: Hardware RAID-5, Smallest stripe

For some strange reason, the Adaptec card did not like this test.  Anyhow, we see again Areca ripping through this test.

HD Tach RW v3.0.1.0, 32MB Zones: Hardware RAID-5, Smallest stripe

Areca is beating up the others like before. 

ATTO Disk Benchmark: Hardware RAID-5, Smallest stripe

Write Speed, KB/s   Read Speed, KB/s

Now we have some Adaptec data.   A strange pattern is emerging here.  Adaptec is dominating RAID-5 writes in block sizes of 128k and up.  But for all others, Areca is still in the winner's circle. 

HD Tach RW v3.0.1.0, 8MB Zones: Hardware RAID-5, Largest stripe

With the larger stripe size, performance dropped across the board.  Areca maintains strong performance here though.

HD Tach RW v3.0.1.0, 32MB Zones: Hardware RAID-5, Largest stripe

Again, numbers dropped from the smaller stripe size, but better than the 8MB zone test previously.  Areca still strong. 

ATTO Disk Benchmark: Hardware RAID-5, Largest stripe

Write Speed, KB/s   Read Speed, KB/s

In these larger stripe tests, we see HPT-1820A struggle to keep up with the big boys especially in the writes, ouch.  Adaptec eke out wins for the two largest chunks in reads only.  Areca takes most of the tests rather convincingly.