Quick as a flash: A quick look at IBM FlashSystem
The TMS acquisition forms the foundation of IBM’s FlashSystem products. There are two main lines: the 900 Series, which is a flat out dragster product and the V9000, which combines 900 series appliances and IBM’s SVC (SAN Volume Controller) to provide the scalability and features that aren’t present in the standard appliance.
Looking at the speeds and feeds, the FlashSystem 900 claims latency numbers as low as 90µs (write) and 155µs (read), although these are minimum rather than typical values. Throughput is a claimed 1.1m IOPS (100 per cent random read) with 4KB block size and 600,000 IOPS (100 per cent random write) or around 800,000 IOPS with a 70/30 per cent read/write split.
Bandwidth is quoted at 10GB/s (100 per cent sequential read) and 4.5GB/s (100 per cent sequential write), so a more balanced workload probably sits somewhere in between as 100 per cent sequential isn’t typical in anyone’s book. For an all-flash product, these are good numbers. However, we have to remember that with the exception of RAID-5 support, there are no other native features in the 900 Series platform. A single 900 Series array is limited to around 105TB in capacity (raw) or 57TB usable after RAID-5 overhead is taken into account.
FlashSystem 900 uses custom-made flash media, branded by IBM as MicroLatency modules. These use a mix of 20nm MLC flash NAND, FPGAs and software IP deliver a bespoke #storage medium. This direction is also being followed by Violin Memory with VIMMs, Pure Storage with FlashBlade and Hitachi with FMDs.
IBM completed the acquisition of TMS (Texas Memory Systems) in October 2012. The company (TMS) has a long history of developing memory-based storage products, based initially on DRAM and later SLC and eMLC technology. I looked at the ramsan range years ago as a potential customer and my abiding memory is the relative cost of the hardware compared to today’s all flash systems. However, that was at a time before EMC had started to introduce SLC drives into VMAX and Violin Memory was only a twinkle in the founder’s eye.