Memory Performance on various Embedded Systems

Marcin just published an interesting article about memory performance on various embedded systems using the hdparm -T as a simple benchmarq.  This test gives a pretty good indicator of memory performance in the system.  From the hdparm man page:

Perform timings of cache reads for benchmark and comparison purposes.  For meaningful results, this operation should be repeated 2-3  times on an otherwise inactive system (no other active processes) with at least a couple of megabytes of free memory.  This displays the speed of reading directly from the Linux buffer cache without disk access.  This measurement is essentially an indication of the throughput  of  the processor, cache, and memory of the system under test.

A few results I find interesting:

  • modern desktop systems have an order of magnitude more memory bandwidth than ARM systems.
  • the i.MX31 is the highest performing ARM device tested
  • the i.MX31 performs better than the OMAP3 in this test — why is this?  As the ratio is 2, I’m guessing the bus is twice as wide?