Forums - is snpe_bench on 888 HDK

I'm running performance test of a simple Mask R-CNN model on 5 different Snapdragon 888 Mobile Hardware Development Kits and I'm finding that the most recent boards that I received are running much faster than some boards that a year older.  I'm using the Android OS that came with the devices, I have not modified them.

This is the output of "uname -a" to show the different android versions that are in these boards, you can see that they are essentially the same version "5.4.61" but have different dates.

Fast: Linux localhost 5.4.61-qgki-g02c90c6 #2 SMP PREEMPT Wed Apr 14 11:57:49 PDT 2021 aarch64

Slower: Linux localhost 5.4.61-qgki-g60d1f93 #1 SMP PREEMPT Tue Nov 24 09:51:58 MST 2020 aarch64

The change in performance is significant as shown below, on average it is about a 50% speed up which is crazy.  This is using SNPE snpe-1.64.0_3605, and so my question is, when I update SNPE SDK versions, do I also need to reflash the boards to a newer version of the operating system?  Are the two things tied together in terms of getting the best possible performance?  If not, does any one have any idea why there is this much variation depending on when you buy the boards, because I thought the hardware components were identical... ???

board_2492867a = [5022, 5577, 5935, 5769, 5779]
board_be77134d = [5342, 5275, 5697, 5312, 5077]
board_a4b2cfcb = [5416, 5417, 5405, 5382, 5255]
board_e6dc0375 = [3010, 3003, 2975, 3009, 3001]
board_f85154f6 =  [3101, 2977, 3157, 3142, 3178]