Those are some very strange data, I have never seen anything like that. Here is what I can tell you..

First thread to check out is here:

http://www.empirisoft.com/support/showthread.php?t=55

Also see the trouble shooting section in the guide. In particular the section titled: System or Software Trouble, following the advice regarding narrowing down any potential correlates--e.g., certain computers, different versions of DirectRT, etc. Also, check out the bit about sending us a dxdiag.txt file from one of your machines. The section is also online here:

http://www.empirisoft.com/directrt/h...leshooting.htm

With that said.. In looking at your data file, my guess is that you have some system event happening occasionally outside of DirectRT that is limiting the processing capacity of other programs. If you sort your trials by the "Order" column, it looks like these trials are occurring in clusters. Of course, I'm look at just one file so maybe validate this with your other files.

If this is the case, the first thing I would look into is what else you have running on your systems at the same time. There can be a lot of stuff running that is not immediately apparent. Do you have an IT person there who can help you track down the other processes that are running during your sessions?

I would also look at disconnecting from the network during sessions. I have heard of this causes momentary interruptions in processing capacity.

See also: www.empirisoft.com/Support/showthread.php?t=70

Most of all, I would highly recommend to always look at log files of test sessions before running actual subjects. Remember that DirectRT can not handle any given set of presentation times just because it's told to do so. A number of factors can have an impact on timing, and the log files are there to show you whether or not you can get what you want on the computers you have.

Also, just curious, what version of DirectRT is running on these machines and are these the same machines you had the previous graphics issues with (see www.empirisoft.com/Support/showthread.php?t=600)?