In the recent SR reviews of the Crucial C300 LSI 9260 MegaRAID SATA 6.0Gbps, the drive was tested using a LSI 9260 MegaRAID SATA 6.0Gbps controller with a 512 MB cache. The Crucial drives showed average performance on SATA 3.0 compared with Sandforce drives, and much higher performance on SATA 6.0 I don't believe the performance gains were solely due to the SATA 6.0 bandwidth, but that the tests were heavily influenced by the LSI card and its cache.
Why weren't the other brands of drives tested on the LSI card (it is SATA 3.0 compatible) to provide a benchmark of the performance improvement attributable to the card?
In the conclusion of the review, "Price has come down making for an excellent value proposition" - not true, because to achieve the results an expensive controller card must also be purchased.
"even low-end 6.0Gbps adapters have problems. We tested the HighPoint Rocket 620 6.0Gbps add-on card at the start of this review and saw incredibly slow performance. With the latest drivers, it was still performing sometimes at half the speed of the Intel ICH10R. Switching to the LSI 9260 MegaRAID card solved all of these problems, so a compatible card is the key to unlocking the C300's complete performance. "
So really, this review is a review of the LSI card, not of the Crucial drive.