yes scaling has not been good, part of it was firmware, when i ran those i did it with 1.42 FW for the vertex which is slower, and those results are definitely not optimal. try running cached i/o on the 9260 and see if that helps your sequential, there is some settings for acards that would not be the same though. my typical read for this setup with 9260 is 1450 so the scaling is not perfect. there is also the question of burst speeds etc, i run the i/o meter with a 5 sec ramp to avoid burst readings.