cl-mem is an OpenCL memory benchmark utility.
Version 0.2 tests sequential write and read speeds. Version 0.3 added sequential copy. Random read/write tests are planned for a later version.
example R9 380 with memory clocked at 1.5Ghz:
Running write test.
128 GB in 1150.1 ms (111.3 GB/s)
Running read test.
128 GB in 779.5 ms (164.2 GB/s)
Running copy test.
128 GB in 906.2 ms (141.3 GB/s)
cl-mem uses code from Marc Bevand's SILENTARMY zcash miner