Here's something from the FAQ: "The latest versions of our software (shown below) do support both of these technologies. Our software is multi-threaded, so it will take advantage of using dual CPU's or Hyperthreading. The level of support varies in each program, but it is not going to double the speed of the software. Due to shared resources within Windows, even fully optimized software rarely maxes out both (real or virtual) CPU's. Both the Main Concept MPEG encoder and the Windows Media encoder are optimized for hyperthreading, so there is a performance increase when rendering to those formats. Also, the DV encoder within Vegas is optimized for HT and dual CPU's, which gives a speed increase when rendering to DV AVI."

So it looks like only some functions will benefit from using multicores. Hmmmm.

I would say it would be worth your money to go with a quad. I jumped from a dual core 5000+ cpu to 8 cores skipping quad all together. I can only take advantage of 8 cores in 8.1 on Vista 64, but I can use 4 cores just fine in 8.0. Others here have reported that 4 cores give a great bump over two.

j razz

1) It really depends on what format you are rendering - and which FX etc. you use.. and
2) one thing is specifications and theory - another thing is real life:

I have a Mac Pro with double Xeon quads. I just rendered something to wmv and no matter how much I try to increase the number of rendering threads it hums silently along with a CPU usage of 13-15 percent :-)))

Just after that I had another job rendering to m2t and here the CPU usage was around 60-70 percent going up to 93 percent where the video was "ironed" with the Neat Video FX and some color correction.
93% of 8 cores compares to 7,5 cores running at 100 :-)

Right now my machine renders to m2t in the background while I am editing in the foreground - and previewing at nearly 29 fps on quality Preview and Half.

All this with 2 GB of memory since XP can not "see" my 4 GB on the Mac. I even have the windows "Paging Executive" disabled giving next to unnoticeable response times when I check my mail etc. besides all the other stuff.

So: absolutely go for a quad or higher. However since some tasks in Vegas and the .NET environment sometimes seem to utilize only a single CPU it is urgent that you also go for a high CPU speed to avoid waiting times there....