Defragmentation without NCQ
We’ll first show you the results of the HDDs without NCQ, i.e. when the AHCI mode is disabled for the HDD in the mainboard’s BIOS. The numbers are shown in one diagram for better readability. Note that we measure the speed of defragmenting a 32GB partition on all HDDs. If you are defragmenting the entire capacity of the drive, the time will be proportional to the HDD size.
The situation has changed dramatically. WD1500ADFD HDD that used to be the defragmentation leader when we tested with the built in Windows XP tool, dropped back to the fourth place and even its 10,000rpm spindle rotation speed didn’t help. The winner’s laurels went to the 750GB newcomer from Hitachi. The second prize was won by Samsung HD501LJ, and the proud third place belongs to 500GB Seagate hard drive from the 7200.10 series. The very last ones to finish the tests were Maxtor drives, which suffered from the much lower data density per platter and WD5000AAKS. Note that the result of the latter is much lower than that of other Western Digital hard disk drives with 7,200rpm spindle rotation speed. For example, the 400GB WD4000AAKS HDD that boasts newer firmware version than its 500GB counterpart, performed almost 375 seconds faster. The server version of the 500GB model – WD5000ABYS – also turned out faster, although just a little bit. By the way, it completed defragmentation over 1.5 minutes sooner than its predecessor – WD5000YS with lower per-platter data density and as a result featuring one platter more.
It is interesting that in the Seagate camp the server ST3500630NS model lost over 40 seconds to the “regular” model from the same generation – the ST3500630AS.
Now let’s take a look at the Seagate hard drives with identical data density and identical storage capacity, but with different cache-buffer. ST3250620AS HDD on two platters and with 16MB cache-buffer is 206 seconds faster than ST3250820AS with the cache-buffer of half the size. The same situation happens to new 250GB models consisting of a single platter: ST3250410AS with 16MB cache outperformed ST3250310AS drive with an 8MB cache by 187 seconds.
Let’s take another look at the same four Seagate hard drives, but this time we will compare with one another pairs featuring identical cache-buffer but differing by the per-platter data density. Newer single-platter ST3250410AS and its younger brother - ST3250310AS are far ahead their older dual-platter relatives: ST3250620AS and ST3250620AS. The defragmentation time difference equaled 110 seconds for models with 16MB cache, and 129 seconds for models with 8MB cache.
So, what is actually better: higher data density or larger cache? The answer to this question depends on the type of tasks the HDD is performing most. But if we try to draw a conclusion from the results of this test, then larger cache will win. If we compare the results of a Seagate ST3250310AS with higher data density and ST3250630AS with lower data density but twice as big a cache, we will see that the latter completes the test 73 seconds faster. However, it was a pretty easy guess, because in this type of tests the hard disk drive doesn’t perform any streaming file copy operations, when higher data density could be the key to success. However, larger cache-buffer helps a lot in efficient file fragments distribution over the clusters.
I would like to draw your attention to the fact that in all comparisons we have just discussed, the difference is much larger than the results delta.