A Look At Samsung Magician's RAPID Feature
RAPID is a software-based feature in Samsung's most recent build of Magician. Simply, it uses a gigabyte of system memory for caching hot data. Frequently-used applications are stored in RAM, ideally yielding much faster accesses when that data is needed over and over. Unlike other RAM-based caching solutions, RAPID keeps cached data persistent between reboots by writing information to the SSD itself.
The software is only available in the next version of Samsung's Magician. But by the time 840 EVOs are available, the necessary build should be downloadable. We got our hands on an early version, and although we didn't have much time for testing, we did run some preliminary numbers.
The only requirements are a compatible SSD and Magician 4.2. With those satisfied, click the "Enable" button to reboot your system. Once Windows loads, the driver starts up automatically. Of course, this means you're not accelerating the boot process. But with a fast SSD under the hood, this isn't something we were concerned about.
You might have missed the orange text at the bottom of our Magician screen capture, but RAPID is specifically prevented from interacting with multiple drives. It's not clear whether this is an artificial or truly technical limitation.
The quickest way to verify that RAPID is on and working is to run a canned benchmark. Magician has its own test module, but we went ahead and used CrystalDiskMark for verification. Here's the "before" shot of a 250 GB 840 EVO on a Haswell-based test platform.
Now, for the RAPID-enabled shot:
The performance increase is profound. Writes shoot up, while the read results shoot up as well. But we still had to wonder if RAPID was just a marketing gimmick tacked on to a comprehensive management suite. Without much time to delve into the specifics, we chose one workload that's indicative of real-world performance, since it actually derived from real-world performance: our Storage Bench v1.0 trace with RAPID enabled.
| 250 GB 840 EVO | Average Data Rate | Mean Service Time | Mean Read Service Time | Mean Write Service Time |
|---|---|---|---|---|
| RAPID Disabled | 279.54 MB/s | 512.23 us | 237.57 us | 1171.1 us |
| RAPID Enabled | 325.96 MB/s | 252.02 us | 261.32 us | 229.55 us |
Crazy, right? The Average Data Rate jumps from 279 MB/s up to a record 325 MB/s. Mean Service Time (including read and write I/O times combined) drops in half, which is stellar. Read service times actually slide back a bit, perhaps from the overhead incurred when requested data isn't in the cache. But the mean write service time gets the biggest bounce. The reduction there is just awesome.
I'm convinced we need to take a closer look at this in the days to come. For instance, it's not clear if the extra cache layer is problematic in the event of power loss. After all, with RAPID enabled you have the DRAM cache, the SSD's DRAM, the Turbo Write buffer, and then the triple-level-cell storage itself, creating a fairly complex hierarchy.