Dell EMC all-flash XtremIO X2 gains I/O boost via software upgrade

Dell EMC has announced upgrades to its XtremIO all-flash arrays that claimed a 3x boost in capacity per X-Brick node, claiming 80% better response times and increased density that can see 5.5PB fit in a rack.

But what’s under the hood in XtremIO X2 and its XIOS 6.0 operating system? How has EMC achieved those headline figures?

The answer is a combination of hardware upgrades to its central processing unit (CPU) and random-access memory (RAM), plus a large dose of software changes – in particular to the way input/output (I/O) is handled and its compression algorithm.

On the hardware front, the processing power in its X-Brick nodes – comprising a drive bay plus dual controllers – has been enhanced, with a change up to 48-core Intel Haswell CPUs.

Also, RAM has been increased to 1TB in the general workload-focused X2-R X-Brick (with capacity that scales from 34.5TB to 138.5TB) and to 384GB in the low capacity-high I/O-focused (for example, virtual desktops) X2-S node (7.2TB to 28.8TB).

X-Bricks can be scaled to a raw capacity of 1.1PB, or a claimed 5.5PB effective. On the drive front, the X2-R now comes with 1.92TB flash drives, while the X2-S comes with 400GB capacity solid-state drives (SSDs).

Meanwhile, X-Brick drive bays have been boosted in size from 25-drives to 72, and X2-S nodes can also scale to four X-Bricks and X2-R to eight.

On the software side, the upgrade to the XIOS 6.0 version of the operating system has seen improvements in two key areas: compression, which is boosted by 25%, and a claimed boost of 80% improvement in latency.

While compression changes come from improvements to the data reduction algorithm, the I/O changes come from “a write boost that allows us to deal better with small blocks,” said XtremIO senior vice-president and general manager Dan Inbar.

“In essence, we have shortened the I/O flow. We looked at writes on systems out in the field and noticed small blocks were taking a lot of time, so we gave the system the ability to deal with writes at an earlier stage in the process,” said Inbar.

Claimed I/O performance is 220,000 input/output operations per second (IOPS) for one X-Brick and 880,000 for a cluster of four, with an average latency of half a millisecond across the board.

Also, in a move counter to storage trends, XtremIO now allows scale-up as well as scale-out additions to its systems, in which just drives can be added rather than entire controller or drive bay nodes.

Host connnectivity is Fibre Channel and internet small computer systems interface with Infiniband as a back-end connection.