This is a somewhat curious SSD that doesn't work like the others in the roundup. It is designed to work hand in hand with Intel's new Smart Response Technology, which is available on the recently released Z68 chipset. It is designed as a cache drive which is then paired with a normal hard drive. Much like Seagate's ‘Hybrid' Momentus XT drive from last year the firmware then works to cache the most used data, effectively boosting your PC performance with minimal interaction.
The Intel 311 SSD also differs from the other drives here in its construction. Because the priorities for a cache drive are different to those of a boot drive, Intel has gone for high quality Single Level Cell (SLC) flash memory. This is ultimately more expensive per gigabyte than the commonly-used Multi Level Cell (MLC) flash, but because this is designed for caching Intel can get away with a smaller capacity than that needed for a boot drive, which lets it balance out the costs. (While the 311 wasn't shipping at the time of writing, Intel has quoted a USD price of around $110 for the 20GB drive.)
Unfortunately the nature of the drive means that our normal benchmark doesn't work on it. Because of the nature of caching it isn't an easy thing to test smart response. Some office focused benchmarks highlight the difference, but because the data caching is automated in the background, you never know if a drive benchmark is testing data on the HDD or SSD. If you are planning on building or upgrading to a Z68 system, this is a very viable option that you should consider, delivering near-SSD speed with little to no involvement beyond initial setup.