phoronix benchmarks ext4 vs. btrfs

[Michael Cronenworth]

Chris Murphy wrote:
> Well, most of my colleagues and customers with desktop systems have rather extreme storage requirements. Individual files multi gigabyte composited image files. So an SSD is nice for speed, but cost prohibitive for everything to be stored on SSD. What they need is a file system that puts hot files on the SSD and cold files on HDD. I think there is btrfs code being worked on to do just that. I don't know if it's any more or less difficult to do this on other filesystems.

Yes, such a feature was submitted[1], but it has never been committed by 
Chris AFAIK. There is also a OS-agnostic method of this. Seagate XT 
drives use a small SSD as a cache. Then there is also a Windows method 
with Intel's SSD Cache using a dedicated SSD as only a cache. Either way 
gives you a similar result.

[1] http://lwn.net/Articles/400029/