Winding up this section of the review we will offer you diagrams with graphs for five different queue depths. They show what firmware the HDDs have very clearly.

Among the Hitachi drives the old 7K1000 is good enough but has a slump in the middle of the graphs. The picture changed dramatically on the transition to the 7K1000.B series: NCQ is less efficient at long queue depths but more efficient at short queue depths. Deferred writing got worse, too. When the HDD was again equipped with 32MB of cache in the E7K1000 series, deferred writing improved, but there was no progress in terms of reordering numerous write requests. It looks like the drive has got a shorter maximum length of the reordering queue.

Samsung’s products are odd, too. The desktop F1 DT either has problems with NCQ algorithms or its firmware is optimized for lower noise: a HDD just should not be slower at 100% reads than at 90% reads. The enterprise version is all right when it comes to reading but its deferred writing is suppressed. The firmware doesn’t seem to be perfect because ideal firmware doesn’t have such sudden fluctuations of performance.

Seagate’s 4-platter 7200.11 model looks good. It has excellent NCQ algorithms and effective deferred writing. But we see quite a different thing with 3 platters: the reduced performance at reading may be explained by the drive’s having too slow actuator in order to produce less noise. But what about writing? Why is there this barrier at 60 operations per second? The performance only grows up somewhat at a queue depth of 256 requests when the controller driver’s reordering algorithms come into play.

The Seagate SV35.3 is quite an incomprehensible thing. It totally lacks NCQ and has almost no deferred writing. Its performance is as low as to resemble some prehistoric HDD. Seagate offers very odd drives for video-oriented applications.