The Intel Optane Memory M10 (64GB) Review: Optane Caching Refreshed

Test Procedures

Our usual SSD test procedure was not designed to handle multi-device tiered storage, so some changes had to be made for this review and as a result much of the data presented here is not directly comparable to our previous reviews. The major changes are:

• All test configurations were running the latest OS patches and CPU microcode updates for the Spectre and Meltdown vulnerabilities. Regular SSD reviews with post-patch test results will begin later this month.
• Our synthetic benchmarks are usually run under Linux, but Intel's caching software is Windows-only so the usual fio scripts were adapted to run on Windows. The settings for data transfer sizes and test duration are unchanged, but the difference in storage APIs between operating systems means that the results shown here are lower across the board, especially for the low queue depth random I/O that is the greatest strength of Optane SSDs.
• We only have equipment to measure the power consumption of one drive at a time. Rather than move that equipment out of the primary SSD testbed and use it to measure either the cache drive or the hard drive, we kept it busy testing drives for future reviews. The SYSmark 2014 SE test results include the usual whole-system energy usage measurements.
• Optane SSDs and hard drives are not any slower when full than when empty, because they do not have the complicated wear leveling and block erase mechanisms that flash-based SSDs require, nor any equivalent to SLC write caches. The AnandTech Storage Bench (ATSB) trace-based tests in this review omit the usual full-drive test runs. Instead, caching configurations were tested by running each test three times in a row to check for effects of warming up the cache.
• Our AnandTech Storage Bench "The Destroyer" test takes about 12 hours to run on a good SATA SSD and about 7 hours on the best PCIe SSDs. On a mechanical hard drive, it takes more like 24 hours. Results for The Destroyer will probably not be ready this week. In the meantime, the ATSB Heavy test is sufficiently large to illustrate how SSD caching performs for workloads that do not fit into the cache.

Benchmark Summary

This review analyzes the performance of Optane Memory caching both for boot drives and secondary drives. The Optane Memory modules are also tested as standalone SSDs. The benchmarks in this review fall into three categories:

Application benchmarks: SYSmark 2014 SE

SYSmark directly measures how long applications take to respond to simulated user input. The scores are normalized against a reference system, but otherwise are directly proportional to the accumulated time between user input and the result showing up on screen. SYSmark measures whole-system performance and energy usage with a broad variety of non-gaming applications. The tests are not particularly storage-intensive, and differences in CPU and RAM can have a much greater impact on scores than storage upgrades.

AnandTech Storage Bench: The Destroyer, Heavy, Light

These three tests are recorded traces of real-world I/O that are replayed onto the storage device under test. This allows for the same storage workload to be reproduced consistently and almost completely independent of changes in CPU, RAM or GPU, because none of the computational workload of the original applications is reproduced. The ATSB Light test is similar in scope to SYSmark while the ATSB Heavy and The Destroyer tests represent much more computer usage with a broader range of applications. As a concession to practicality, these traces are replayed with long disk idle times cut short, so that the Destroyer doesn't take a full week to run.

Synthetic Benchmarks: Flexible IO Tester (FIO)

FIO is used to produce and measure artificial storage workloads according to our custom scripts. Poor choice of data sizes, access patterns and test duration can produce results that are either unrealistically flattering to SSDs or are unfairly difficult. Our FIO-based tests are designed specifically for modern consumer SSDs, with an emphasis on queue depths and transfer sizes that are most relevant to client computing workloads. Test durations and preconditioning workloads have been chosen to avoid unrealistically triggering thermal throttling on M.2 SSDs or overflowing SLC write caches.