Message-ID: <4D90EDB6.2080609@2ndQuadrant.com>
Date: Mon, 28 Mar 2011 16:21:10 -0400
From: Greg Smith <greg@2ndQuadrant.com>
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To: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Intel SSDs that may not suck
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Today is the launch of Intel's 3rd generation SSD line, the 320 series.  
And they've finally produced a cheap consumer product that may be useful 
for databases, too!  They've put 6 small capacitors onto the board and 
added logic to flush the write cache if the power drops.  The cache on 
these was never very big, so they were able to avoid needing one of the 
big super-capacitors instead.  Having 6 little ones is probably a net 
reliability win over the single point of failure, too.

Performance is only a little better than earlier generation designs, 
which means they're still behind the OCZ Vertex controllers that have 
been recommended on this list.  I haven't really been hearing good 
things about long-term reliability of OCZ's designs anyway, so glad to 
have an alternative.  *Important*:  don't buy SSD for important data 
without also having a good redundancy/backup plan.  As relatively new 
technology they do still have a pretty high failure rate.  Make sure you 
budget for two drives and make multiple copies of your data.

Anyway, the new Intel drivers fast enough for most things, though, and 
are going to be very inexpensive.  See 
http://www.storagereview.com/intel_ssd_320_review_300gb for some 
simulated database tests.  There's more about the internals at 
http://www.anandtech.com/show/4244/intel-ssd-320-review and the white 
paper about the capacitors is at 
http://newsroom.intel.com/servlet/JiveServlet/download/38-4324/Intel_SSD_320_Series_Enhance_Power_Loss_Technology_Brief.pdf

Some may still find these two cheap for enterprise use, given the use of 
MLC limits how much activity these drives can handle.  But it's great to 
have a new option for lower budget system that can tolerate some risk there.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books