Comparison Products & Test Notes
We had a limited amount of time with Optane Memory before launch, so we were not able to test all possible configurations. We plan to write a follow-up article that explores Optane Memory in more diverse conditions. That includes a system with a small amount of system memory, a notebook battery life test in a system equipped with the RAID Option ROM (OROM), and a full test suite using an Optane Memory SSD as the secondary storage device.
We use the Intel 600p SSD to represent a value NVMe SSD that could benefit from Optane Memory acceleration, but due to Optane Memory restrictions, we could only test it with RST caching. That doesn't provide the full benefit of the technology, such as preloading white-listed operating system files to the cache device. There are also a number of new DRAM-less products on the market, but due to time constraints, we couldn't test the new Corsair Force LE 200 or other DRAM-less SATA models.
We used a Seagate BarraCuda Pro 10TB as our hard disk drive. The BarraCuda Pro is the fastest 3.5" consumer HDD on the market. It allows us to examine the vast performance gap between an HDD and an entry-level NVMe SSD, as well as quantify the acceleration power of Optane Memory. In a future article, we'll also test with a mainstream 2.5-inch notebook hard drive to represent a more modest user group.
Intel isn't the only company with storage caching technology. Several other companies also released DRAM-based acceleration products when Smart Response Technology came to market in 2011. NVELO introduced Dataplex software, which came with products from Corsair, Patriot, and OCZ, to name a few. Samsung later purchased NVELO, and now Dataplex serves as the core technology behind Samsung's Rapid Mode. We include test results with a Samsung 850 EVO 500GB both with and without Rapid Mode enabled.
Other companies have released cache acceleration software that leverage system memory (RAM) to increase performance. Crucial enabled the feature as part of the Storage Executive suite. It's important to understand that these technologies use RAM to increase storage I/O instead of a separate SSD DRAM module, so you'll need more system memory to make these technologies effective. System memory prices, like NAND flash, rise and fall based on demand. Currently, both NAND flash and DRAM pricing are at high tide. That makes Optane Memory more attractive now than it would be if NAND and DRAM were more affordable.
To help us better represent the target market, Intel sent us a pre-configured system with Optane Memory. The system consists of a Core i5-7500 processor, B250 motherboard, 16GB of DRAM and a 1TB Western Digital hard disk drive, but it lacks a discrete video card. The mainstream system is a far cry from what we normally use for test hardware. I'll be the first to admit there is a disconnect between our normal test systems and the components an average consumer uses inside their PC.
We had to ramp up the new test platform because Intel only officially supports Optane Memory on Intel's 200-Series chipsets and some 100-Series notebook chipsets.
Mainstream users are the target market for Optane Memory. This group doesn't spend a lot of time optimizing motherboard firmware settings or Windows like enthusiasts and power users. With that in mind, we ran our tests with settings that are representative of an OEM-type system, so some of the performance data in our charts will look dissimilar to our usual storage reviews. We enabled C-States and other power-saving measures. These features reduce system responsiveness and storage performance. We conducted all the tests on the Windows 10 boot device and dialed back system cooling represent a mainstream PC. This will allow the thermal throttling that could happen on a mainstream PC.
Rapid Storage Technology offers two caching modes; Enhanced (write-through) and Maximum (write-back). Due to time constraints, we were only able to test the Intel 600p NVMe SSD/Optane configuration in Enhanced Mode. This is how Intel defines the two modes:
Enhanced mode (write-through) is the default mode of operation where acceleration is optimized for data protection. In this mode, all data is written to the SSD and HDD simultaneously. In the event the accelerated disk fails, there is no risk of data loss, because the data on the HDD is always synchronized with the data in the SSD. Since this mode is optimized for data protection, there is a performance impact since all writes slow down to HDD speeds. However the HDD and SSD pair may be physically separated without any special precautions to preserve data.Maximized mode (write-back) enables acceleration optimized for input/output performance. This mode captures most host writes into the SSD first and updates the copy on the HDD during available system idle periods. This enables a considerable boost in write performance and also saves power. However, Intel Smart Response caching must be disabled prior to HDD and SSD physical separation. If it is unlikely that the HDD and SSD may be physically separate or an SSHD is being used, then maximized mode is recommended for best performance and responsiveness.
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