FC-Test: FAT32

The last test set, which we are going to use this time is our favorite FC-Test. If you are not yet familiar with this benchmark, please consult our article called “X-bit labs Presents: FC-Test for Hard Disk Drives”.

The main peculiarity of our HDD file copy testing methodology is the way the files sets on the HDD tested are created and read. We measure how much time it takes to create a certain set of files on the HDD (in other words, we measure the write speed) and to read these files from the drive afterwards (which is the average read speed).

The second important peculiarity is the fact that we do not use any synthetic files sets to test the drives (this could make the task a lot easier). For our tests we use absolutely real files taken from a real PC. That is why we claim that we test the hard disk drives in real conditions. Especially since many of you surely have a folder called Windows or MP3 on the drive :)

The third peculiarity, which is quite unpleasant, unfortunately, is the fact that our test uses operation system calls that is why the results are very dependent on the OS status at the time you run the test (paging file content, disk cache status, etc.). We can ensure more stable results by making a paging file of some fixed size and starting the test immediately after Windows restart (of course, only after the startup is complete). Also numerous iterations may also be of some help :)

So, let’s check the HDDs performance, and to be more exact, the performance of several HDD + controller combinations in FAT32:

All results in MB/sec are summed up in this table. The diagrams below will make the analysis more illustrative:

As we see, with smaller files (Windows and Programs patterns) all HDDs perform equally fast. But as soon as the average file size grows bigger than the cache buffer of some hard disk drives (the average files size in MP3 pattern is 3.65MB), the beautiful ordered picture disappears immediately…

SATA hard disk drive with Promise SATA 150 TX2 Plus (WB) controller takes the lead, and two SATA drives of different storage capacities, namely 120GB and 80GB, with SiliconImage controller follow closely behind the leader. And just a tiny bit behind we find an 80GB SATA drive with Promise SATA 150 TX2 Plus (WT) controller.

Note that the best result shown by an ATA HDD is still over 20% worse that the worst result shown by a SATA HDD. Moreover, this best result among ATA drives belongs to a 120GB HDD with 2MB cache-buffer. It is all natural that it outperformed the 80GB drive, because the 120GB model has a bigger cylinder and hence can write a bigger data block per single pass. But how come that the solution with an 8MB cache-buffer fell so far behind? No clue…By the way, the results obtained in FC-Test contradict the results obtained in HDTach: which test to you personally trust more then? :)

In the ISO pattern the leading positions get occupied by SATA drives with SiliconImage controller and the performance of a SATA HDD with Promise SATA 150 TX2 Plus controller appears absolutely independent of the requests caching mode. It is interesting that ATA HDD with 120GB storage capacity and 2MB cache-buffer is still much faster than its counterpart with 8MB cache-buffer.

And in Install pattern (the average file size is 1.4MB), the initiative again goes to a SATA drive with Promise SATA 150 TX2 Plus (WB) controller. It manages to get about 2.5MB/sec (10%) ahead of the closest rival.

Well, writes seem to be much better performed by SATA HDDs. And what about reads?

And when reading, the SATA drives no longer have any advantage over their ATA analogues. The only combination, which managed to show a noticeably different result is a SATA drive tested with Promise SATA 150 TX2 Plus (WB) controller. Although this time the influence is just the opposite: we saw performance improvement with writes and here we see a significant performance drop! What’s the matter? Could it be high CPU workload that limits the performance of the disk subsystem? Or maybe the WB algorithms of the controller get in conflict with the read ahead algorithms of the hard disk drive? To tell the truth, we have no definite answer yet…

Well, now that we have already checked the read and write speeds, let’s combine these two modes. We are about to start the actual copy tests.

Just in case let me remind you that for FC-Test the HDD tested should be formatted as two logical drives of equal size and the copy tests will be carried out within one logical drive as well as between the two logical drives.

At first we are going to copy the preliminarily created file set within the same logical drive:

A quick look at all this mess pushed us to make a few comments. Firstly, SiliconImage controller is a definite winner here: it showed the best performance for all file sets.

Secondly, WB-caching seems to make sense during copy operations. And thirdly, an ATA drive with 8MB cache-buffer has finally shown its real power. Do you see the tremendous difference between the results shown by the same 120GB models differing only in the cache-buffer size? I assume this is very convincing evidence of the large cache-buffer advantages.

When we copied file sets from one logical drive to another (the heads have to be moved to longer distances than in the previous tests), the situation remained almost the same. The only thin worth mentioning is the improvement of SATA-drive’s performance with Promise SATA 150 TX2 Plus controller working in WB mode.

Again the ATA-drive with 8MB cache-buffer is much faster than its brother with the 2MB cache-buffer.