Hi!
After looking into the new JPEGLS compression I did some benchmarking and found that compression speed was somehow sub-par as far as my expectation were going.
So I dismissed the JPEGLS migration but now, since I got some spare time, looked back into it and I was pretty much kicked in the nuts from what I just found out.
OK here is the deal:
If you use Windows or Windows Server with Xeon CPUs the standard performance scheme is "balanced" - this sounds quite fine as this is what most users actually want, powersaving in idle but ramping up clockspeed via Speedstep when needed.
However when in "balanced" mode Windows does not scale your CPU up to the max frequency when there are just a few threads with high CPU utilization (the more cores you have the more likely this issue appears) - even with prime95 my CPU sits below 2Ghz with 2 threads running prime - only when I add more threads it scales up to 2,4Ghz, but even then it is not using its boost frequency.
Since conquests JPEG compression is single threaded I was loosing a lot of performance here!
Solution:
Set windows power scheme to "performance", click "advanced properties" and scroll down to CPU and set minimum frequency from 100% to 5%.
Now Windows will scale the CPU much quicker, will finally use your CPUs Turbo frequency (which is disabled in "balanced" mode) and will use low frequencies when idle.
To give you some performance figures:
scheme "balanced" JPEG LS lossless: 19 images/s -> scheme "performance" : 26 images/s which is +30%
scheme "balanced" NKI compression: 26 images/s -> scheme "performance" NKI compression : 35 images/s
cheers