Crucial RealSSD C300 (256GB, SATA 6Gb/s)
Crucial provided its M225 drive for review a few months ago, and we included it in the first part of this roundup. That drive was based on the Indilinx Barefoot controller. However, since Crucial wanted to be the first SSD vendor to reach SATA 6Gb/s, it decided to utilize a different controller and interface.
Being part of Micron, Crucial has a significant advantage over other SSD vendors. The company can simply use its own in-house MLC flash memory for SSD products. Samsung and Toshiba also make their own chips, and Intel pulls its NAND from the IM Flash Technologies (IMFT) company it shares with Micron. Other memory brands all rely on third-party suppliers for their memory, controllers, or even entire drives.
Aside from the SATA 6Gb/s interface spec, all of this drive's other relevant specifications sound familiar. You'll find TRIM support, low idle power, a wide operating temperature range, a three-year warranty, and impressive performance numbers, especially for read throughput. Crucial says this drive can deliver up to 355 MB/s.
On one hand, the RealSSD C300 is undoubtedly the first SSD to break the 300 MB/s line. We measured up to 308 MB/s and minimum read throughput of 293 MB/s. In this context, the competition now appears somewhat out of date. We saw similarly impressive results in all of our I/O performance testing, including 4K read and write testing. The RealSSD C300 is also strong in many PCMark Vantage tests.
… and Issues
Unfortunately, performance inconsistency in write throughput and some PCMark Vantage routines remains, occasionally producing extremely low write performance numbers. While the drive can write at almost 200 MB/s, we saw it drop to only 12 MB/s in worst case scenarios. Given that we could restore optimal performance through a full erase, this throughput crater most likely results from remaining issues with TRIM in Windows 7. Problems could rest with the firmware, but they could also be linked to the Marvell controller. If the controller doesn’t pass TRIM commands, then write performance will keep degrading.
We’ve been in touch with Crucial about this since early March and actually delayed our roundup, hoping that Crucial could provide updated firmware. Hopefully, future firmware versions will help to maintain the excellent performance levels we’ve seen. Kelly Sasso, media relations manager at Crucial and Lexar Media, said that implementing the improvements has proven more time consuming than initially anticipated. Regardless of existing issues, the drive still has the potential to become a real high flyer. We just advise against purchasing it today.