Sunday 7th April 2013 7.23am

Sun, Apr 7, 2013

It occurred to me that for my workstation an upgrade of its Renesas USB 3.0 controller's firmware might help: it now has firmware 3034 and driver v2.1.39. And look at the difference it makes: 86Mb/sec reads and 63Mb/sec writes for that Sandisk Extreme Pro microSDHC. Write speeds are still a good bit below what they should be, but I ain't complaining.

For comparison I threw in a Sandisk Ultra UHS-I microSDHC, and it gets 43Mb/sec reads and 9Mb/sec writes. Note the hard drive like write latency of 8ms or so.

One BIG concern is the random 4Kb writes which are awful even by SD card standards - I think they sacrifice random access for throughput in these newer fast cards. Must admit I can see me turning off barriers, any form of write guarantees etc.

So, on to finding a SD card with reasonable random read and write scores …