RamSan the Green Solution

In a recent research project I compared the energy consumption of SSD based technology to IOPS equivalent disk based fibre attached SAN systems. As you can well imagine the SSD technology was much more space efficient, required less cooling and of course less electricity while providing faster data access.

But just how much can be saved? In comparisons to state of the art disk based systems (sorry, I can’t mention the company we compared to) at 25K IOPS, 50K IOPS and 100K IOPS with redundancy, SSD based technology saved from a low of $27K per year at 2 terabytes of storage and 25K IOPS to a high of $120K per year at 100K IOPS and 6 terabytes of storage using basic electrical and cooling estimation methods. Using methods documented in an APC whitepaper the cost savings varied from $24K/yr to $72K/yr for the same range. The electrical cost utilized was 9.67 cents per kilowatt hour (average commercial rate across the USA for the last 12 months) and cooling costs were calculated at twice the electrical costs based on data from standard HVAC cost sources. It was also assumed that the disks were in their own enclosures separate from the servers while the SSD could be placed into the same racks as the servers. For rack space calculations it was assumed 34U of a 42U rack was available for the SSD and its required support equipment leaving 8U for the servers/blades.

Even figuring in the initial cost difference, the SSD technology paid for itself before the first year was over in all IOPS and terabyte ranges calculated. In fact, based on values utilized at the storage performance council website and the tpc.org website for a typically configure SAN from the manufacturer used in the study, even the cost for the SSD was less for most configurations in the 25K-100K IOPS range.

Obviously, from a green technology standpoint SSD technology (specifically the RamSan 810) provides directly measurable benefits. When the benefits from direct electrical, space and cooling cost savings are combined with the greater performance benefits the decision to purchase SSD technology should be a no brainer.