Data Center Tech Blog

SanDisk®’s announcement of shipments of the ULLtraDIMM solid-state drive (SSD) for servers is demonstrating the deep impact and the business benefits that placing flash storage directly next to the server’s processors can have. The combination of flash-based SSDs and server DIMM slots is synergistic—producing a change that dramatically accelerates application performance.

ULLtraDIMMFlash technology has long been packaged in products that can be plugged into SAS, SATA and PCI-e I/O interfaces – and its positive effects on workload acceleration are already well understood. But the ability to “skip” a trip through the traditional I/O software stack – and to reside directly on the DIMM slots of server – takes SSD latency reduction to a new level.

Clearly, speed is a key benefit for the new ULLtraDIMM. The Ultra Low Latency (ULL) —baked into the name of the product — is measured to be as low as 5 microseconds, just a fraction of the multi- milliseconds latency that is inherent in hard-disk drives (HDDs).

Scaling Up with ULLtraDIMM

Many ULLtraDIMM SSDs can be housed inside the same server — bringing multiple TB of memory extremely close to the system’s microprocessors. That means that the memory bus connected to the DIMM slots is controlling the data-transfer rate. This reduces the data-transit time, avoiding a trip through the inside-the-system I/O stack.

ULLtraDIMM ScalingSanDisk has worked with Diablo Technologies Inc. to incorporate its Memory Channel Storage (MCS) technology into the ULLtraDIMM SSD. That technology links the DDR3 channel to the ULLtraDIMM storage housed in the server DIMM slots.

Scaling up with ULLtraDIMM memory was shown last fall, when a server with up to eight ULLtraDIMMs was demonstrated to the public at the SuperComputing Conference 2013 in Denver. As shown, the ULLtraDIMM deployments support near-linear scaling of flash storage capacity. Each ULLtraDIMM SSD brings up to 400GB of flash storage, per DIMM slot. So, the 8-slot server installation shown at Supercomputing 2013 included up to 3.2 TB of storage. If more DIMM slots were used in a vendor’s server, many more TB of data would be located close to the system processors.

In coming months, customers should expect to see new servers from Tier 1 vendors incorporating ULLtraDIMM – and being shipped into the marketplace. These will likely be 4-socket and 8-socket servers running data-intensive workloads – aimed at markets such as financial services, oil & gas, and retail. All of these markets are data-hungry and customers run extensive Analytics programs to find the “patterns in the data” to inform business insights – and take business actions as a result.

Why Should Customers Care?

Why should customers care about this approach to near-in memory? It’s the effect it has on their applications and databases – which are accelerated by the co-location on the same sector of the server motherboard. Looking down the server’s technology stack from an application-centric view, rather than from a hardware-centric up view, the work will get done more quickly – and will be able to keep pace with increasing end-user demand for access to the application.

A broad range of applications and databases will be supported for use in many types of environments, including datacenters running mission-critical workloads, datacenters adopting virtualized infrastructure — and those designed for cloud computing. A future blog will focus on a portfolio of workloads that will benefit from ULLtraDIMM technology.

Another dimension to the ULLtraDIMM story is that it will preserve customers’ data, because flash SSDs provide non-volatile memory. In the event of an outage in the datacenter (e.g., power outage, network outage or failure of other hardware components), the data in ULLtraDIMM will be retained, making it available when the power is restored to the server. That supports business continuity.


ULLtraDIMM is a new way to extend server capabilities by adding flash directly into a server’s DIMM slots, using near-in flash storage. SanDisk, working with Diablo Technologies on the memory channel, is pioneering this DIMM-slot-compatible innovation for servers. This technology will be flowing into the marketplace in 2014, shipping in generally available servers in coming months. I’ll be taking a closer look at customer workload examples in my next blog post – so stay tuned!


Follow Jean S. Bozman at @JBozman or join the conversation with @SanDiskDataCtr
To keep up with the latest ULLtraDIMM news, use #ULLtraDIMM  and #UltraLowLatency hashtags.

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