Why is Compressor 4 so darned slow?

Hello all,

Using Compressor 4.0.6 and FCX 10.0.7. Have a few iMac's, all core i7's, 2011 or later, all with a minimum 8GB Ram. The projects I create are on average 2 hours long, and I produce about 160 of them a year.

I've exhausted trying to find answers on the dicussion forums and online and I can't figure this out. I'm probably an idiot overlooking something, so I'm here seeking guidance.

I finally completely dived into FCX this past month after all the great updates. I LOVE the program. There's been some growing pains getting myself up and running, but I'm pretty much to the point where my workflow is becoming second nature like it was in FC7.

But, Compressor 4 is leaving me stumped. Here's my issue. If I take a master H.264 file that I produced from FCP (7 or X, doesn't matter), that's between 8-10GB's in size and put it in Compressor 3, not changing anything about it's native settings or anything with Q-Master and/or clusters (picture installing it, then instantly create a DVD image file from a master H.264... not touching any preferences), it'll shoot out a disk image file in about 2 hours for me. A Bluray image in maybe 3-4 hours.

This all using i7 quad-core processors in iMacs.

If I try to do the same in Compressor 4, it might take 4-6 hours to produce a DVD image file. 6-8 hours for a Bluray image file.

This isn't isolated to one computer, but on any computer I try. It's PAINFULLY slow. Being 64bit, I was expecting it to be twice as fast as C3.

Then I got into clustering and Q-master and all of that. I've spent days trying to get it right with a lot of trial and error. But whenever I create a cluster following tips on these very forums and others that match the specs of my machines, there will be no dramatic increase in these speeds and most of the time I'll get some crazy number like 36 hours to process. In which case I turn the virtual cluster off and have to settle for the usual 4-8 hour timeframes for it to spit out files (whether they be DVD files for Bluray).

Can somebody with extensive knowledge of C4 please tell me why it's not fater than C3 (I'd be happy with equal results) and what, if anything, I'm doing wrong.

If it helps, one of the computers I'm using is an iMac quad core i7, 2.93ghz, 8GB ram. Just want to throw that out there so if anyone wants to offer "step-by-step" instructions on how to maximize the power of C4 for me on one computer (not interested in daisychaining imacs, yet), they have the vitals for one of my computers that I'll apply those settings to and hopefully figure this thing out.

Thanks to any help or advice in advance!!