[x265] Regarding new thread pooling: Low CPU utilization on Dual Xeon

[Mario Rohkrämer]

There have been several reports already that the current x265 binaries are  
not very efficient since a new thread pooling was introduced.

One of the members of the German speaking doom9/Gleitz video board -  
'Massaguana' - reported a very low utilization, ~25-30% overall, on a dual  
socket board:

2x Intel Xeon CPU X5675 @ 3.07GHz
logical processor count: 24 (2*6 physical cores *2 with HT)

He is running encoding tests on MacOS X 10.10.2 via Hybrid (by Selur) and  
Handbrake (here he is also discussing crashes with certain parameters in  
their forum).

Attached is a screenshot of a per-core CPU utilization bar indicator. As  
you can see, only few cores are used at all, and they even quite little.  
Apparently these threads are waiting a lot for each other? More details -  
some logs and screenshots - in German in this thread:

http://forum.gleitz.info/showthread.php?46557&p=449737#post449737 (ff.)

It would certainly help to evaluate the thread pooling better if there  
were some sample values available, at least for a typical single-socket  
quad-core, possibly one with HyperThreading, and dual-socket systems.  
Preferably in some of the famous forums (doom9, VideoHelp) and the online  
documentation.

In return, Massaguana will be happy to offer tests on his machine. In the  
meantime, he will discuss with Selur how to add pme and pmode to the  
parameters in Hybrid...

-- 

Fun and success!
Mario *LigH* Rohkrämer
mailto:contact at ligh.de
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