IBM Pushes FlashSystem Costs Down To Nearline Disk Storage

March 3, 2025 Timothy Prickett Morgan

If flash storage is ever going to replace disk storage, and there are good reasons to believe that at some point it will, this will happen because flash becomes normal and offers a mix of technical and economic reasons why it is worth a small premium – not a huge one, mind you – compared to buy dirt cheap spinning rust.

IBM’s new FlashSystem C200, which debuted last week in announcement letter AD25-0017, might be just the thing that small and medium Power Systems customers have been waiting for.

It has been a dozen years since IBM bought flash array upstart Texas Memory Systems for an undisclosed sum, very likely hundreds of millions of dollars. TMS was interesting in that its RamSan product line mixed IBM’s PowerPC processors and Xilinx FPGA accelerators to create the memory controller for the flash array, and then hung SLC and MLC flash off those controllers to create different levels of IOPS, durability, and capacity. The fattest machine, the RamSan-820, which became the FlashSystem 820 at Big Blue, had 24 TB of MLC flash in a 1U rack form factor with 4 GB/sec of data bandwidth. Yielding 450,000 IOPS at 110 microseconds for reads and 400,000 IOPS with 25 microsecond latencies for writes. We never knew prices for this array, so we don’t have a “compared-to-what” point of reference.

But we do with the FlashSystem 840 that was announced in January 2014 as a kicker to the FlashSystem 820. The FlashSystem 840 came in a 2U form factor, and it has 48 TB of MLC flash in the chassis. The minimum write latency on the FlashSystem 840 was around 90 microseconds and the minimum read latency was around 135 microseconds, which was a bit slower on the reads and quite a bit slower on the writes. But the IOPS were more than 2X as high. The base FlashSystem 840 cost $32,000 with no flash in it, and fully loaded with a dozen 4 TB “flash cannisters” as TMS and IBM call them, this machine cost $680,180. That worked out to $14,170 per TB of raw capacity. IBM bundled its SAN Virtualization Controller (SVC) inside of this box, which it claimed offered 5:1 data compression. We have no idea if that was realistic for back office applications.

In any event, $14,170 per TB for any flash storage sure didn’t price like a midrange product to us at the time.

Flash forward – pun intended – to the FlashSystem C200, which has two cannisters with a pair of eight-core X86 processors, each with 128 GB of main memory, as its controllers. (There are two controllers in the machine, for a total of 32 cores.) These controller cannisters (what we usually call sleds in modular designs) link out to two dozen 46 TB FlashCore Module (FCM) QLC NVM-Express flash modules. The flash array has eight 10 Gb/sec Ethernet ports (four per cannister) and up to four additional 32 Gb/sec Fibre Channel I/O adapter slots if you want to use that instead of Ethernet to link the flash array to your server. That works out to 1,104 TB of raw capacity in the same 2U of capacity, and IBM says that it can deliver 5.5X more write cycles than industry standard QLC flash thanks to the cleverness of its engineers. And it is guaranteeing at least 2:1 with its hardware data compression.

Compared to disk arrays using 16 TB disk drives – like the kind that you probably bought from IBM either under the skins of your Power Systems server or in a Storwize external array – IBM says that the FlashSystem C200 can deliver 2.4X better read performance. (We don’t know about write performance.) The FlashSystem C200 is rated at 23 GB/sec of data throughput. Here’s the real kicker: At $381,000 fully loaded, that 1.1 PB of raw capacity costs $345 per TB. That is a factor of 41.1X reduction in cost per raw TB. And at a minimum 2:1 data compression ratio, and taking some of the capacity away to save it for wear leveling over the course of five years, you are down to an effective $249 per TB. (The 1,104 TB of raw is made into 766 TB of usable capacity, and with compression, that is a minimum of 1,532 TB of effective, usable capacity.)

That price is coming closer to a near-line storage array based on fat disk drives spinning a leisurely 7,200 RPM. So close, in fact, that it doesn’t matter anymore.

The FlashSystem C200 will be available on March 21. The announcement letter does not say what operating systems are supported with the FlashSystem C200, but it had better include IBM i as well as AIX, Linux, and Windows Server.

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