8 Core Mac, 16 instances?

[Cmayeux]

I have a Mac Pro with 2 x 2.26Ghz Quad Core processors.

I am currently in the process of clustering it with a Mac Pro (2 x 3Ghz Dual Core) using Apple Qmaster that comes with Final Cut Studio.

When setting up the 4 core in Qmaster, it gives me the option to select the number of instances (cores) to use during compression. It allows for up to 4 which makes sense because it only has 4 cores.

However on the 8 core it allows for up to 16 instances. This puzzles me as I am pretty confident it is only an 8 core system and should only allow for 8 instances. Is there something I don't know about the guts of that machine or is Qmaster mistaken?

 

[Umbongo]

Your 8 core has hyper-threading enabled which the software sees as 16 logical cores.

http://www.intel.com/technology/platform-technology/hyper-threading/index.htm

 

[beaker7]

I would do some experimenting with how many instances is optimal.

If you spawn 16 of them, you're also asking your ethernet connection to support 16 instances pulling footage at the same time.

Might be better off with 4 instances on an 8core/16thread machine depending on how well the given encoder supports multiprocessing.

 

[Cmayeux]

Thank you for your replies. I have never heard of hyper threading but that sounds like its good.

I have set up 4 instances on the 8 core Mac which is also the cluster controller and I have set 4 instances for the services only Mac which is a 4 core machine.

I have set up this cluster in Qmaster Administrator and the cluster is showing 4 instances from both Macs (8 total). It is recognizing the services only Mac and its 4 cores that are available for processing but when I begin compression of a video, it only uses the cluster controller (8 core mac) and not the other one.

I don't understand because it clearly is recognizing the other computer and its cores and shows that it is a part of that cluster but it will not use it, only the main computer.