Three PCI Express-Based SSDs: When SATA 6 Gb/s Is Too Slow

Benchmark Results: 4 KB Random Reads/Writes

Iometer 2008.08.18 4 KB Random Testing

The Fusion-io ioDrive is clearly the best perfomer when it comes to 4 KB random reads. LSI’s WarpDrive gets close at a queue depth of four, and even overtakes at a queue depth of 16 or higher. But on average, Fusion-io stays on top.

The situation is different in 4 KB random writes, as LSI’s WarpDrive dominates the overall result pretty clearly. It is almost twice as fast as the other drives at increased queue depths. The OCZ Ibis comes in second, and the Fusion-io drives seem to lose ground quite a bit. Let’s verify this with AS SSD.

AS SSD 4 KB Random Testing

Fusion-io comes out on top again for 4 KB random reads.

However, the WarpDrive overtakes with a bang at a queue depth of 64. It seems as if more work is beneficial for 4 KB random read performance for all drives, but while most drives improve by 3x to 6x, LSI’s WarpDrive is at least 20x better.

At 4 KB random writes and limited queue depth, all drives perform in the area of 70-100 MB/s.

However, cranking up the number of pending write commands increases performance up to almost 700 MB/s. Keep in mind that this is on random 4 KB writes, and not sequential writes with larger block size (where we'd expect to see higher throughput), so these results are deeply impressive.

Fusion-io’s ioDrive delivers the most balanced performance, while the LSI WarpDrive shows the highest performance potential. OCZ disappoints a bit in this test, as the Ibis delivers a 4 KB random write speed on a used medium that isn’t too different from the performance of a single SSD.