How much are you paying for your fast storage? Recently I have seen more and more people from the blogosphere talking about replacing plate spin hard drives with Solid State Drives (SSD) on laptops, desktops and even servers.
I have gone through the same path. My homelab run its system’s primary partition on a SSD Kingston 128GB SSDNow V+. The performance when loading Window or any other application installed on the SSD is really good – at least much better when compared to most plat spin hard drives.
However, last week one of my customers brought to my attention that some SATA III plate spin hard disks on the market are actually as fast as a Solid State Drives (SSD). More specifically I am talking about the Western Digital VELOCI RAPTOR. This SATA III hard disk has capacity of 600GB, 10000RPM and 32MB Cache. Using PassMark – Disk Mark to compare it to the most common SSDs on the market this HD does not disappoint.
Top End SSDs
Common SSD Range
WD VELOCI RAPTOR (WD6000HLHX)
See full list of benchmarks here
Next I had to compare price per Gigabyte for the most common hard drives and also some of the top end. The dollars in this list are in AUD but it should reflect approximately the same parity anywhere.
When comparing the PassMark – Disk Mark from the VELOCI RAPTOR with the Kingston SSD the difference is not that much; however when comparing the price per GB we see a significant difference. The VELOCI RAPTOR is almost 5 times cheaper than SSD, at the same time as the Disk Mark demonstrate a difference of only 68 points on performance
Both drives I mentioned in this article are based on SATA III architectures. The SATA III bus has a maximum specification of 6 Gbit/s when utilizing all 10 channels available; reaching throughputs of 500 MB/s and over. Fortunately the disk technology available today, at least off the shelf, does not fully utilise this capacity. As an example, the Veloci Raptor will only reach a maximum read throughput of 157.1 MB/s in a sequential transfer.
There is a good article about the WD Veloci Raptor here if you are interested in reading more.
Off course I could not miss the opportunity to discuss VDI and VMware View. In January, 2010, I have published an article named “Expensive storage array not required for VDI?” where I introduced the idea of running virtual desktop on SSDs. Recently VMware also published a document entitled “The VMware Reference Architecture for Stateless Virtual Desktops with VMware View 4.5” reinforcing that same idea for some very specific VDI scenarios.
As technology evolves SSDs and ESSDs will reach that maximum 6GB/s SATAIII limit, but by then we will hopefully have other architectures available at reasonable cost. In the meantime I would recommend you looking carefully on the type of throughput your workload (homelab or production) require and make de proper decision.
The decision might be even easier when you think about creating redundant disk topologies. As an example, 3 VELOCI RAPTOR in a RAID5 setup will provide better throughput, more storage disk space, more reliability/redundancy than 2 Kingston 64GB at a less expensive cost.