SSD Caching Benchmarks: PCMark Vantage
By default, Intel uses a write-through strategy to keep data synchronized between the SSD and the hard drive. If you lose power or experience a SSD failure, no data is lost. This is what Intel calls Enhanced mode in its RST software. When you write to your hard drive, you write simultaneously to the SSD.
In comparison, Maximized mode gets a performance benefit from write-back caching. This involves synchronizing data between the SSD and hard drives in intervals, though. If you choose to go with that caching policy, a power loss means that information not synchronized can be compromised. Intel claims that a pre-boot recovery process will automatically restore the correct cache state though, and that the risk is similar to a mechanical hard disk running with its internal write cache enabled.
You'll notice that we're testing with three different SSDs. The idea, of course, is to figure out how much performance you need from your solid-state device to get maximum benefit from Smart Response Technology.
PCMark Vantage paints a rosy picture of better performance with SSD caching enabled. But once you look at the individual test suites, you understand why. Remember that Intel's algorithm is "smart." It deliberately tries to avoid caching large chunks of data read sequentially, assuming that sort of usage pattern is only going to be touched once by the user. That's our explanation as to why caching doesn't help improve performance in the TV and Movies suite.
The current cache strategy specifically places a priority on application, user, and boot data. Photos are smaller, do get cached, and the Memories suite benefits as a result.
If you read our review of Crucial's m4, then you know the drive should achieve an HDD suite score above 50 000 PCMarks. This graph helps illustrate that caching with an SSD is in no way equivalent to letting the SSD run unfettered. At the same time, Crucial's m4 has a profound impact on performance compared to Seagate's Barracuda XT on its own. The hard drive's maximum outside-diameter data rate of 138 MB/s is still a far cry from the m4's 260 MB/s sequential write speed.