PA Server and performance failure

LOL cpu limited......2600K @ 4.5ghz is one of the fastest cpus out there.

Yes it is.... However as PA can only use 1 thread for the rendering engine you only have 1/8th of the CPU available. The GPU was only working at around 40%, so the CPU was the bottle neck (which you can see from the fact that the PA.exe thread is using 12.5% of the CPU or 100% of 1 thread on an 8 thread CPU).

In this instance you could probably boost PA performance by turning off hyper-threading (therefore increasing the resources allocated to each thread at the cost of the 4 additional threads), and also you need to ensure core parking is disabled as this can reduce the clock speed on a particular core resulting in much less performance.

This is the problem with modern CPUs, it's no longer about the speed as much as the processors ability to use the resources available effectively. It's also part of the reason AMD are struggling so much as they sacrificed single thread performance in the pursuit of adding more cores- when software can make use of all the threads on offer an AMD FX 8 core CPU can keep up with an i7, however 9 times out of 10 the software can't effectively make use of the cores and so the FX chip gets smacked about by an i5 with its much higher per core performance.

In the case posted by the OP this is worst case scenario for PA as a spectator gets the visibility for all units all the time. This is what overloaded his CPU (and also his internet bandwidth). There are allot of changes coming that will improve this situation, however I do think it's a shame that the PA client render engine can't actually run on more than one thread (however multi-threaded render engines are *very* hard to code so I can understand). As I understand it the PA server software is multi-threaded so it will get a significant boost from a chip like an i7, however for the client single thread performance is all that matters so there isn't really that much difference between a modern i3 or an i7 for client performance (at stock clocks at least).