Well the 8 core machine is going to be the faster of the two, but you'll need 16 gigs of RAM...2 gigs per core. without it you have a sluggish boat anchor. with it you have a rocket with 8 apps open at a time while you check your email and download files while AE renders and Compressor compresses and DVDSP builds a disc and Toast burns one.
FCP doesn't use the extra cores, so for FCP the choice is irrelivant. For AE, the previous post is spot on. Check out barefeats for a good comparison of benchmarks of mac pros. For AE you want as many cores as possible and 2GB per core.
[moody glasgow]"FCP doesn't use the extra cores, so for FCP the choice is irrelivant"
This is currently true, but I think the consensus is that when Apple finally release FCS3 and Snow Leopard, this could/should be a different story. Plus we can already make use of multiple core processing with Compressor, and I don't know an FCP user who doesn't use Compressor.
Personally I'd want to be buying the machine that I know will hold up better in the months and years to come. As people have said here before, spending a little (or quite a lot) more on hardware isn't a bad thing because our business should be covering those costs long before they're replaced. If it won't then it probably makes more sense dry hiring a top suite as and when it's needed.
The 2.93 ghz 8-core is smoking fast, but will cost you at least $6K. So it depends on how much you want to spend.
Oh I forgot to mention that the new 4-core systems only have 4 memory slots, another reason to stay away from it.
[johnsabbath d'urzo]"I want to get rid of my G5's and pick up a Mac Pro. I'm using FCP and AE a lot with beta sp and have an Aja LHe and also want to move into HD. "
If you're running an G5, unless you're running a G5 Quad 2.5 with PCIe architecture, you're running the AJA Kona LH which will not work in a new Mac Pro. Please tell us which Mac you are running to confirm whether it's an AJA Kona LH or LHe.
As for the new machine, get the fastest machine you can afford with a minimum of 8GB matched RAM.
why wouldn't you get a used machine? Actually I never picked up a used on either i always bought mine new. Is there anything I should look out for? what is the reason that you don't buy used? this is coming from a store as a trade in, should i trust it?
I agree with the Apple refurb with Apple Care. Some used machines are just lemons. Something jiggy in the RAM modules or the processor itself. Something quirky in the ethernet card etc. Apple tests their machines before putting them up in the store, but still get the Apple Care and a pile of RAM and you can't go wrong.
Oh, and plan to get an SATA 500gig - 1 terabyte drive to slip into the second drive slot under the main drive. Best $89 you can spend.
You would think the 8 cores means machine #1 is faster, but since it has a mere 2GB RAM (even less RAM than the quad machine), it won't perform very well unless you dump more $$ into RAM. As everyone has mentioned, you really should have 2GB RAM per CPU core if you want to max out the machine's potential. The more cores and less RAM you have, the lower each core will perform and therefore having 8 cores doesn't do you that much good. If it were me I would go with the 8-core, but budget for a lot more RAM. Can't afford it, get the quad.