As a concept, a PCIe based SSD is a smart way to enjoy the advantages of RAID0 without having to buy two separate SandForce-based SSDs and messing up with many installation settings, as long as it is reasonably priced. Especially if you are dealing with large and compressable files and you need your SSD to operate under really heavy loads, then RevoDrive is your solution.
Although this RAID0 array of two SandForce controllers hidden behind a PCI Express interface is able to give you as much as double the performance of a single SSD, this performance heavily depends on the the situation. According to out tests, the RevoDrive will not be as fast as you may expect in every and any scenario .Specifically, it seems that SandForce’s DuraWrite compression technology is relatively slow when dealing with incompressible data, such as is used in the AS SSD benchmark. This is the case with the Revo, as we saw it manage a sequential read speed of 319MB/sec and a sequential write speed of just 90.37MB/sec rather than the quoted 540MB/sec and 450MB/sec. This performance is close that of some single SSDs. Of course, the same test showed that when the drive accessed/wrote 100% compressed data, the performance was increased to meet the drive's specifications.
We also experienced some surprising low sequential read and write results in the full benchmark of the HDTachRW test. On the other hand, when the same benchmark used many smaller and thus more compressible files for the sequential test, the RevoDrive maxed out at around 425MB/s for write and close to 500MB/s for read, especially when it was accessing /writing files larger than 128KB.
In Iometer, which randomly reads and writes three consecutive patterns of 4KB files, the Revo was also not as fast as expected. In the reading part, compared to single SandForce-based SSDs, the RevoDrive was nearly twice faster. The performance during writing depended on the queue depths. In low queue depths, the random write performance was as low as what you may expect from a single SSD. But if you increase the queue depth for a particularly intensive workload, the the RevoDrive will take the lead. In addition, the drive showed impressively low response times.
Every benchmark uses different methods of measuring performance and some benchmarks appear not to be able to measure SSD performance, while others are somewhat better.
With these results in mind, we believe that the majority of desktop users aren’t pushing this many IOs at a given time so for them, the 50GB RevoDrive could not be the best solution for them, compared to a pair of SandForce-based SSD, which will additionally offer the benefits of TRIM support. On the other hand, if you plan to add your SSD under heavy loads, then the RevoDrive is a good solution, provided its good price.