Why is the ART VM slower than the Dalvik VM, at sorting an array when the array size is 62000? Look at row 62 of this graph.

It is the time taken for a quick sort integer array, on a VM for android 4.4 (KitKat). How come that ART is faster except at an array size of 62000? In fact, it is significantly slower than Dalvik, as Dalvik takes 238 seconds, but ART takes 333 seconds. The result does not even fit the pattern of results, in rows 61 and 63. I could even say that its anomalous.
This is very strange. Why does this happen?
Most probably the test is inconsistent. Have you tried repeating the test at least 100 times to have pseudo-valid statistic results? And are you sure the emulator is a valid platform on where to test such low-level things? It may be optimised for the Dalvik VM.

Best guess is to try it on a real device, like the new Nexus 5 or waiting for the Nexus 4 and Nexus 7 updates.