In our previous article about RAID arrays we built them out of 400GB hard disk drives. Now we want to check out 500GB products as well.
The increased storage capacity (for a RAID0 it now equals the pretty-looking number of 2 terabytes) is only one aspect of the issue. More importantly, 500GB drives generally have higher recording density and, consequently, higher speeds of processing sequential data. While all the HDDs in our previous review were based on three platters, this test session includes a few HDDs with only two platters and four heads although their capacity is higher. We want to find out how they perform in RAID arrays and how much faster the new higher-density models are in comparison with the older generation. And there is also the factor of firmware that is being improved by the developers from model to model. How effectively will the RAID controller work with the new HDDs? Will the simultaneous use of the controller’s own cache and the HDDs’ cache memory be efficient? These questions do not have obvious answers and it is better just to check them out in the practical way.
Participating Hard Disk Drives
500 gigabytes is far from the maximum storage capacity available today but such HDDs feature a low cost of storage. Thus, they offer an opportunity to build a large and inexpensive array of the high-performance RAID, fault-tolerant RAID5 or in-between RAID10 type.
Of course, we cannot compare all 500GB hard disk models available on the market. There are too many of them for that. The test session would take too much time and the resulting report would be too long for anyone to digest. Therefore we will only take eight models from different makers.
The first two HDDs come from Hitachi’s and Samsung’s desktop series. They are not new (newer models with two and three platters are available already) but are inexpensive, so thrifty users are going to consider them in the first place.
The next pair comes from Seagate: they are similar to the previous two models in characteristics. The difference is that the Barracuda 7200.10 is a desktop HDD whereas the Barracuda ES is meant for professional applications, i.e. for high-load 24/7 servers. You will see shortly if there is any difference in performance between these two models.
The next pair represents Seagate’s newer 7200.11 and ES.2 series. The enterprise and desktop models both feature increased recording density and each achieves the capacity of 500 gigabytes with only two platters. The cache memory of both models is increased to 32MB.
And the last pair in this review is from Western Digital’s enterprise RE2 and RE3 series. The newer RE3 disk has higher recording density and, like the abovementioned drives from Seagate, gets along with only two platters. As opposed to them, it has 16 megabytes of cache, like the older products in this review. So, we will be able to see what advantage the larger cache gives to Seagate’s products.