Diablo has been selling a NAND flash-based memory module for a couple of years, accessed as block storage, like a disk, but much faster. Their new product, Memory 1, is a byte-addressable - like DRAM - flash DIMM, that dramatically expands server memory capacity.
More and more applications are moving to in-memory designs for performance. It's not uncommon for big servers today to have hundreds of GB of memory to support virtualization, analytics, caching, databases, hyperscale and more.
But DRAM has problems at such scale. At $8/GB, it's costly, and can easily cost more than the server it is sitting in. It sucks power and requires more cooling. And with all that, it can be hard to reach the capacity big apps require.
Enter the dragon
Diablo's new flash DIMM has several cool features:
- Complies with DDR spec
- Standard DIMM form factor
- Up to 256GB - 4x DRAM - DDR5 memory module
- Up to 4TB in a 2 socket system
- Much more economical than DRAM
- No server, OS or application changes
Since flash is persistent and doesn't require refreshing - the D in DRAM - it also uses 70 percent less power than DRAM. Double cool.
Why DRAM isn't going away
While the Diablo guys are wizards, they haven't repealed the laws of physics - or markets. Be aware that:
- You still need DRAM in the system. Diablo suggests a 10:1 ration of flash DIMM to DRAM.
- It requires a software shim - like a driver - to manage the use of all memory in the system. Think of the DRAM as a high-speed cache and staging area for the flash.
- The software shim is available for Linux, Windows and WMware today. Mac support is coming later.
- You can't buy it today, unless you're a massive consumer.
About that last point: it will take a while for production to ramp up, so Diablo is focussing on the low-hanging fruit - web-scale data centers - to begin with. It isn't clear how long it will take before you can buy a couple of sticks online.
The Storage Bits take
The big win is the servers you don't buy, because you can run more memory constrained jobs per server. Which is one reason Diablo is focusing on the web-scale market, since Amazon, Google and Microsoft create their own market. Imagine Amazon getting 10x the work out of a $100M data center by adding flash DIMMs to 50,000 servers.
Over the longer term however, this technology - or ones like it - will trickle down to the enterprise and, eventually, our personal machines. Less power, lower cost, higher memory capacities are all good for us and the planet.
As more non-volatile memory and storage products come to market - and our outdated storage stack is modernized - we'll see massive increases in performance from the CPUs that aren't getting faster as they did in the 1990s.
It's a win for us all. Congrats to Diablo for an innovative and needed product.
Comments welcome, as ever. What would you do with a 4TB server?