Monthly Archives: January 2019

Are SSDs Approaching Price Parity with HDDs?

July 2007 HDD vs SSD Price AnalysisA recent Storage Newsletter article argues that SSD prices are approaching HDD prices, and that the gap has narrowed to only a 2.7 times difference.

Upon closer inspection, though, the reader will note that this is only true at lower capacities.  The narrowing price gap at lower capacities has always existed in this market.  The SSD Guy was making that  argument back in 2007!

This post’s graphic shows a chart from the first report ever published by Objective Analysis over a decade ago: The Solid State Disk Market – A Rigorous Look.

The point of this chart was to illustrate that, at low capacities, SSDs are cheaper, while at higher capacities HDDs provide lower-priced storage.

The concept is simple: It’s uneconomical for an Continue reading

A New Spin on Memcache

IBM DataStore LogoData centers that use centralized storage, SANs or NAS, sometimes use servers to cache stored data and thus accelerate the average speed of storage. These caching servers sit on the network between the compute servers and storage, using a program called memcached to replicate a portion of the data stored in the data center’s centralized storage. Under this form of management more-frequently-used data presents itself faster since it has been copied into a very large DRAM in the memcached server.

Such systems have been offset over the past five or more years thanks to the growing availability of high-speed enterprise SSDs at an affordable price. Often direct-attached storage (DAS) in the form of an SSD within each server can be used to accelerate throughput. This can provide a considerable cost/performance benefit over the memcached approach since DRAM costs about 20 times as much as the flash in an SSD. Even though the DRAM chips within the memcached server run about three orders of magnitude faster than a flash SSD most of that speed is lost because the DRAM communicates over a slow LAN, so the DAS SSD’s performance is comparable to that of the memcached appliance.

There’ a catch to this approach, since the DAS SSD must be Continue reading