Western Digital releases NVMe HDD with a sacrifice in performance and 96TiB memory capacity

Source: 　　Editor: Jessie Update Time :2018-11-13

Although DRAM memory particle has a downside in Q4, there are still two problems of memory for industries such as server and data center. One is low overall capacity of memory, the other is expensive cost in expanding large capacity of memory. And it is a test to realize tens of TB level memory capacity. Western Digital puts Ultrastar DC ME200 hard disk into market earlier, which is a memory expansion drive to be precise. It adopts U.2 or HHHL AIC specifications, with DRAM memory inside rather than NAND flash chip. And its maximum expanded memory is up to 96TiB under 4U server.

Western Digital Ultrastar DC ME200 hard disk is prepared for data center market, aiming at reducing convential memory, huge capacity growth by adding Ultrastar DC ME200 hard disk and reduction of TCO total cost. To get a better understanding of this concept, Western Digital gives and example as follows:

Traditionally, server is configured with 1.5TB DRAM. If using Ultrastar DC ME200 hard disk, memory capacity will be up to 2TiB with a 25% reduction of TCO cost. And using combination of Ultrastar DC ME200 hard disk will reach 3TiB capacity with same cost.

Is there price for Ultrastar DC ME200 hard disk with cost reduction and increasing capacity? The answer is yes. It can be seen that DRAM performance is affected by shifting to PCIe channel from DIMM slot. After all, the bandwidth of PCIe 3.0 x4 supported by NVMe, while the bandwidth of DIMM memory is tens of GB/s or over. According to the test released by Western Digital, the performance of Ultrastar DC ME200 memory hard disk decline, but total performance degradation of the combination of memory and Ultrastar DC ME200 hard disk is decreased by from 100% to 91% or 85%, which depends on configuration. Whether it can be accept or not depends on manufacturer’s demand.

Specific to Ultrastar DC ME200 hard disk, its specifications is as follows:

There are two forms of Ultrastar DC ME200 hard disk, which are U.2 15mm and HHHL specifications. It supports PCIe 3.0 x4 channel. Its power consumption is 9W when standby and 25W in active mode. Its capacity falls into 1Tib, 2Tib and 4Tib. The eight-way CPU in 4U server is configured with 96TiB extended memory in maximum, and supports Intel Xeon E5/E7 v3 and servers range from bronze, gold, silver or platinum.

As for reliability, Ultrastar DC ME200 hard disk itself uses DRAM particle(correction: According to The Register report it uses 15nm MLC flash inside). Its reliability is much more higher than ordinary flash memory, data writing speed is PBW rather than TBW. 4TiB model has a 78PBW data longevity with three-year product warranty.

The price is not mentioned, it starts sampling now and actual release date hasn’t been announced yet.