On 3/30/13 at 2:32 PM, (Simon Blackledge) wrote:
Why non-sandforce for compressed data?
the sandforce controller does on-the-fly real-time compression of data when reading/writing to disk. this doesn't allow you to store more total data (ie capacity doesn't increase), but the I/O can be accelerated significantly in some cases.
like, lets say a typical DPX of a reasonably clean image can be compressed 2:1, that means even if the flash memory chips on the SSD can only read/write 250MB/sec of actual data, you'd still get about 500MB/sec of I/O.
with EXR, they will usually be compressed already, so there's no gain and you might be stuck with 250MB/sec on a disk with slow flash memory (but as others have mentioned, you'll probably be limited by decoding speed anyway rather then I/O at that speed).
a controller with on-the-fly compression can also be helpful because nuke writes uncompressed RGB for cache files (somebody correct me if i'm off track with this).
then again a lot of modern SSDs are already limited by the SATA3 interface bandwidth (around 500MB/sec) rather then by the controller/flash storage (this is where PCIe flash cards come in, or why you have to raid several SSDs to increase bandwidth), so for sequential operations other factors become more important. like reliability (some sandforce firmware were buggy for a while, it's better now but a lot of people are still cautious.. intels supposedly are the most reliable), cost, random access, or garbage collection and performance in full/used state (as trim doesn't work on raids, and performance usually slows down when the disks get full or very fragmented).
but the short story is any modern SATA3 SSD on a SATA3 controller will give you a huge boost for little money - just keep some space free if you RAID them and maybe reformat it every few months if you feel any slow down (never had an issue myself, but i don't have particularly heavy workloads).
would be interesting to do some benchmarks for nuke typical workflows, i'd say try the Samsung 840 Pro, Vertex 4, Corsair m4, Plextor M5 and maybe an Intel disk.
++ chris _______________________________________________ Nuke-users mailing list [email protected], http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
