Performance in FC-Test
To limit ourselves with just the basic facts, we don’t put the results of all the patterns in the diagrams, but only those that are remarkable or useful.
However strange, the previous generation of the Vancouvers is the best in the write speed (the first generation looks good, too), while the new devices show nothing impressive. In fact, we can’t characterize the write speed of the 7K250 as low, but we can’t call it high, either. Among curious things there are: the stable advantage of the 250GB models over the other representatives of the 7K250 series and the strangely low results of the 200GB model. Frankly speaking, we couldn’t find the reason for that – the difference in their firmware? Notice also that the increased size of the buffer doesn’t practically affect the write speed.
The read speed mostly depends on the linear data density, rather than on the firmware and other factors, so the new Vancouver generation leaves their predecessors behind in this test, although the gap is diminishing as the size of the files becomes smaller. The sequential read tests of IOMeter showed us that the efficiency of the electronics has degenerated on small-size clusters, and we see a confirmation to that in the real test. The 8MB buffer is of little profit here, probably because IBM’s drives have always been able to effectively use the buffer of a smaller size.