The next generation of IBM's X-series servers will be able to accommodate solid-state Flash drives clipped into their DIMM memory slots, potentially improving the response times of fast-paced enterprise applications.

On Thursday, IBM unveiled the Series 6 generation of its System X x86-based servers. In addition to the novel reuse of DIMM slots, the X6 architecture will also let customers upgrade them to a new generation of processors or memory without swapping in a new motherboard.


Diablo Technologies, a memory technology company, developed Memory Channel Storage (MCS) that 
enables flash on a DIMM module to be accessed by the CPU, instead of using the SATA bus as other 
DIMM form-factor SSD products have. Using a host-level driver and an ASIC on the DIMM, it creates 
a special memory storage layer in flash through which the CPU actually moves data from the RAM 
memory space. It also requires a minor modification in the server BIOS to be supported by the CPU, something 
that three OEMs have currently completed. 

Each DIMM flash module has 16 separate data channels, which are independently addressable. 
This enables parallel data writes by the driver, improving performance over the DMA process 
used by PCIe-based solutions. Specs for ULLtraDIMM are showing 5 microsecond latencies for these 
devices, an order of magnitude better than typical PCIe flash products. This architecture also 
enables up to 63 ULLtraDIMM modules to be aggregated creating 25TB of flash capacity and >9M IOPS in a single server.


Ref: IBM X series servers now pack Flash into speedy DIMM slots
IBM Beefs Up Enterprise X-Architecture With Flash, Modular Design
Heating Up Storage Performance
How to Make Flash Accessible on the Memory Bus
Memory Channel Storage™
ULLtraDIMM: combining SSD and DRAM for the enterprise