The performance of an SSD and a hard drive serve as the ceiling and floor in PCMark’s overall HDD suite. You’ll notice, though, that the first run on the cached configurations is actually slowest of all. However, it takes just one repetition of PCMark to demonstrate the gains made possible using the technology. And given a cache of up to 64 GB, there’s a strong chance that the information you access most often will end up resident on the SSD.
I didn’t graph out every single sub-test from the HDD suite, since they all demonstrate a similar trend. Basically, you get performance slightly lower than a baseline hard drive-only run at first, as the system writes to both SSD and HDD. Then, subsequent accesses come from the SSD, facilitating significantly better performance.
The Maximized cache setting makes its most pronounced difference in the Vista startup benchmark. But we maintain that it’s not worth risking data loss to use the write-back setting.
Read performance from Intel’s X25-V is one of its strengths, and we see the App Loading test push the upper limits of what this SSD can do on its own. Naturally, the first run with caching enabled doesn’t give us any performance benefit, but by the second run through Vantage, we see a pretty solid performance increase.
The effect of caching on boot-up is, unfortunately, pretty minimal. The bare SSD is the benchmark to beat—everything else is roughly equivalent to a Seagate Barracuda XT on its own.
Intel’s documentation claims that caching helps read and write performance. But in Enhanced mode, you’re writing to the cache and hard drive simultaneously, so you’ll really only ever realize improved read performance.
It doesn’t help that the budget-oriented SSDs that’ll be used for caching aren’t the fastest. Intel’s X25-V boasts 170 MB/s reads, but its sustained sequential writes are a paltry 35 MB/s. The Barracuda’s maximum outside-diameter data rate of 138 MB/s gives it a distinct advantage.
That advantage plays out in our file copy benchmark, where we copy a 7.79 GB folder full of files containing the World of Warcraft game to the same drive. This happens fastest on the Barracuda. Incidentally, when we move the folder over to a configuration consisting only of the X25-V, the copy operation takes significantly longer.