Adding Clustor in Compressor – Why am I offered 8 instances when there’s only 4 cores on my MacPro?

[Mark Spano]

[Dave Chavinsky] “Are these instances related to the number of cores in the computer?”

Yes. In your case, the Quad-core represents four actual processors, and each processor has two virtual cores. So 8 is correct in that dialog.

[Dave Chavinsky] “how many instances should I use? I’ve heard the number of instances should be half of however many cores you have unless you have a lot of memory (there is 6GB of ram).”

A general rule of thumb is that you want to be able to offer at least 2 GB of RAM to each process. If you have 6 GB RAM, I would set this to 3 instances. More memory would let you use more instances, and in that case, I always leave at least one full processor (2 virtual cores) free for other system tasks.

[Dave Chavinsky]

Wow, 8 virtual cores. That sounds awesome. Thanks for explaining that, Mark.

I was using a MacPro1,1 with similar stats. 4 cores that were each 2.66GHz and 6GB of RAM, and I was only offered 4 instances. Is my current computer I described above (MacPro4,1) going to be significantly faster with 8 virtual cores (or did the MacPro1,1 have this too and I was just unaware of it..)

How much RAM would you recommend that I get so I can use my cores effectively. I’m using Adobe CS5.5 with After Effects.

Thanks!!

[Mark Spano]

I believe the old Mac Pro 1,1 did not have virtual cores. How much RAM should you get? Well, for Compressor processes, 2GB per instance is a good idea. However since you’re running CS5.5, it’s a 64-bit application that can address oodles of RAM, so the more you put in, the faster Adobe apps will be. Get as much as you can…