David Magda
2011-May-11 15:36 UTC
[zfs-discuss] Intel Z68 chipset and SSD 311 ("Larson Creek")
The press embargo on Intel Z68 chipset has been lifted and so there''s a bunch of press on it. One feature called Smart Response Technology (SRT) will sound familiar to users of ZFS:> Intel''s SRT functions like an actual cache. Rather than caching individual files, Intel focuses on frequently accessed LBAs (logical block addresses). Read a block enough times or write to it enough times and those accesses will get pulled into the SSD cache until it''s full. When full, the least recently used data gets evicted making room for new data.http://www.anandtech.com/show/4329/2 In addition to the chipset (already shipping in the 2011 Apple iMacs), there''s also an SLC SSD:> The big difference here is the SSD 311 comes with 20GB of 34nm SLC NAND. If you remember back to the SSD Anthology, SLC NAND is architecturally identical to MLC NAND. With half the number of data stored per NAND cell SLC NAND not only lasts longer than MLC NAND but it also is much faster, particularly for writes.[...]> The SSD 311 basically offers the performance of a 160GB X25-M G2 but with fewer NAND channels and a much lower capacity. > > Remember this is SLC NAND so despite only being a 20GB drive, it''s priced more like a 40GB MLC drive: Intel expects the SSD 311 to retail for $110. Thankfully you aren''t locked in to only using Intel drives as Smart Response Technology will work with any SSD.http://www.anandtech.com/show/4329/3 Some good pros and cons from Tom''s Hardware of this system: http://tinyurl.com/42rzkyz http://www.tomshardware.com/reviews/intel-z68-express-smart-response-technology-ssd-caching,2938-3.html Plenty of other articles on the subject popping up. I think that the fact that the SSD is SLC and not too expensive would make it useful for ZFS users as well. Given that the ZIL can never be more than half of RAM, it would mean that you could put one in a server that has 40 GB of RAM. Or in a home machine that has, say, "only" 8 GB you could partition 4 GB of the SSD for a ''slog'' device, and the rest for L2ARC cache. In a perfect world it''d have a supercap, but as it stands, I think it''s a good addition to the product choices we have. Hopefully more manufacturers will get on the bandwagon of "small" SLC SSDs now that Intel is helping mainstream this idea by putting it right in their chipsets.