Trends in server platform storage: Cost Effective High Performance Arrays

There has been considerable excitement lately about the direction of storage available on enterprise class server platforms. Recently, Seagate confirmed that SATA hard drives will reach 3TB capacities in the coming months and solid state drive technology is slowly gaining more acceptance in the difficult-to-please enterprise storage arena.

I’ve watched Dell’s OEM customers steadily grow the storage capacities of their fixed systems to the point where today the typical appliance server has double the hard drive spindles than we were seeing a year ago.

The highest performance spinning media is the 15K/rpm 2.5″ SAS hard drives, which are available in up to 146GB capacities, and the big manufacturers are working hard to double capacity.

However, the real sweet spot that balanced performance and cost is with using 10K/rpm 2.5″ SAS hard drives. These drives matured in the market to where they cost less per GB than 15K/rpm 3.5″ hard drives and since you can physically put more into a chassis, the performance of a RAID array will exceed that of the bulkier 3.5″ drives.

If you compare two 600GB 15K/rpm 3.5″ SAS hard drives to four 300GB 10K/rpm 2.5″ SAS drives in a RAID-0 array, the 3.5″ drives cost nearly the same as the 2.5″ drives (based on average retail prices), but the performance in terms of IOPS (transactions per second) will be nearly 40% slower for the 3.5″ drives.

The raw throughput of the four 2.5″ 10K/rpm drives is also significantly faster than the two 3.5″ drives. Because of this, the most ideal solution for high performance spinning media hard drives is to utilize 10K/rpm 2.5″ SAS drives. When looking to build a solution with high performance spinning media storage, the most cost effective and higher-performing solution is to use 10K/rpm 2.5″ SAS hard drives.

Since the cost and performance differentials are so significant, and since the power consumption, physical size, and higher capacity per rack unit afforded by 2.5″ drives is easy to see, there is almost no likelihood that higher capacity 3.5″ SAS hard drive will ever be developed.

Today the highest capacity for a mainstream 3.5″ SAS drive is 600GB, and already 2.5″ SAS drives have matched that. In the future, higher capacities will be added to 2.5″ SAS drives, but not to 3.5″ drives. The manufacturers have already seen that the future is in 2.5″ SAS drives when it comes to high performance traditional spinning media drives.

What are your thoughts on where we’re trending and how do you think it will affect the market?

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About the Author: Franklin Flint