Sometimes SSDs Don’t Improve System Speed
Demartek tests a lot of systems based on various forms of storage.
I really liked an expression that Mr. Martin shared to compare SSDs to HDDs. He said that SSDs cost dollars per gigabyte and pennies per IOPS, while HDDs cost pennies per gigabyte and dollars per IOPS. This is a really good way to think about the strengths and weaknesses of these two technologies. There is every reason to use a mix of both.
Mr. Martin shared several benchmarks Demartek ran on systems that were configured with and without SSDs. In one compelling case he said that the system performance increased significantly up to a point with increasing speed SSDs, then hit a plateau. Demartek discovered that this plateau was caused by the system finding the next bottleneck after the storage bottleneck was eliminated – it was the network.
When the Demartek team upgraded the network from 1Gb/s Ethernet to 10Gb/s Ethernet performance continued to scale according the speed and number of SSDs added to the storage system.
SSDs won’t solve every speed problem, but they are a useful tool in increasing your system’s performance.