HDDs spin continuously and large numbers are needed to meet the aggregate demand of enterprise applications where I/O is the typical bottleneck. A typical high-end HDD supports 144GB of data, 300 IOPS and consumes 20W of power. Adding RAID protection overheads, over 1,000 drives and 20kW are required to support I/O rates of 220,000 IOPS and transfers of 1 GByte/sec. Violin achieves this performance with just 20 flash memory modules (VIMMs) consuming less than 300W of power.
Violin resolves these bottlenecks by reducing latency from 5ms to 200 microseconds, a 25x improvement which significantly increases CPU utilization. This dramatically lowers the need for server memory and CPUs while enabling more efficient virtualization and server consolidation..
PCIe flash cards are faster than SSDs, but are tied to individual servers.
Legacy storage systems featuring SSDs are designed to integrate flash memory within existing HDD enclosures and use software-based RAID controllers. This retrofitting approach results in (delivered) costs of approximately $200 per GByte (RAID-1) and performance in the 10-30K IOPS range with latency typically around 2ms or more. Violin Memory Arrays, on the other hand, can easily integrate into the existing storage network. Costs are now below $20 per GByte and price/performance effectively increases by 500% or more.