1 Reply Latest reply: Jul 18, 2013 6:09 AM by dotcomplex RSS

    OAS causing latency after SSD upgrade




      I recently upgraded the hard drive in a late-2011 macbook pro to a Samsung 840 Pro SSD.  Raw benchmarks were quite fast, but the overall feel of the system became very laggy.  I noticed that boot was very fast and the first 60 seconds or so were extremely responsive.  Unfortunately, after a minute or so, the system became very slow.  Commands which normally take a few thousandths of a second to complete began to take .1 to .3 seconds.


      I narrowed it down to the OAS: whenever it was disabled, the system responded as expected.  When it is enabled (which it would do automatically after a few minutes) the latency returned.


      One thing I noticed about the latency is that it always seems to come in 100ms increments.  A command which normally took around .017 +- .002 seconds to complete (time sha1sum /usr/bin/git) would take either .117, .217, .317, etc.


      I did not notice any issues before the SSD upgrade.  The install was performed by a time machine restore onto the new disk, then TRIM was enabled through Trim Enabler.


      I appear to be running McAfee security 1.1.0 (1309), Anti-malware version 9.1.0 (4478).


      Any ideas what could be causing OAS to slow things down so much?