Conclusion
The results are nothing less than eye-opening. Even though it is obvious that conventional hard drives will not stand a chance against upcoming flash SSD products, it is impressive to see that a little software modification is powerful enough to increase hard drive I/O performance at least by some percentage, and to introduce up to several times more performance in some benchmarks. Keep in mind that this is only about I/O performance, which is most interesting for servers. Throughput can be maximized by short stroking, but it doesn’t really increase.
How Expensive Is Performance?
It is also obvious that a single, decent flash SSD drive delivers better performance per watt than any hard drive array running in a short stroking setup. However, the total cost for a set of hard drives has to be part of your considerations. At this time, one of the Hitachi Deskstar 7K1000.B drives at 250 GB capacity should be available for $45, maybe even less. Getting four of them, limiting the capacity to a reasonable minimum and creating a RAID 0 or RAID 5 array will at least triple the throughput of a single drive, while also multiplying I/O performance. I doubt that any flash SSD at the cost of four of these hard drives ($150), if available at all, would be able to compete with such an array. Looking back at the poor results of recent flash SSD reviews, I wouldn’t want to get one of these low cost SSDs.
You Need RAID
Of course, you will need RAID capabilities on your host system, but even mainstream motherboards offer them these days. RAID 0 is only an option if you need a fast array for temporary data. For a system installation, you should really go for a RAID 5 or RAID 10 array, to make sure that your system survives if one of the hard drives should crash.
Short Stroking Is Powerful
We don’t think that short stroking setups are only interesting for new systems. It makes a lot of sense to look at your existing IT and server infrastructure, and consider the capacities that you actually need. Should performance-sensitive servers only be using a third or less of storage array capacities, we clearly recommend looking at cutting off some storage space and turning it into increased I/O performance. It may help you to delay hardware upgrades for a few months, which might not be what the hard drive makers want to hear, but is probably a good idea in times of economic difficulty.
