iMac G5 vs PowerMac G4 - Which to keep?

I'm a photographer and the desktop will be devoted to RAW and post-processing, so I want to keep the most efficient machine. I really don't know much about hardware, so I can't judge by looking at the hardware overview. Maybe you can?:

G4 -

Machine Model: PowerMac 3,6
CPU Type: PowerPC G4 (2.1)
CPUs: 2
CPU Speed: 867MHz
L2 Cache: 256 KB
L3 Cache: 1 MB
Memory: 2 GB
Bus Speed: 133 MHz
Boot ROM version: 4.4.8f2

Capacity: 131.66 GB

G5 -

Machine Model: PowerMac8,1
CPU Type: PowerPC G5 (3.0)
Number of CPUs: 1
CPU Speed: 1.8 GHz
L2 Cache: 512 KB
Memory: 2 GB
Bus Speed: 600 MHz

Capacity: 74.41 GB


I'd really appreciate if someone could run down for me which would be better for dedicating to Aperture, Photoshop, and processing very large images!

Thanks

The G5 is going to be faster with its larger L2 cache and overall CPU and bus speed even though the HD is smaller in capacity than the G4. You can always install a larger hard drive.

Also I might point out that many folks think a machine with two CPUs is better, however, if software is not compiled to make use of both CPUs (most software is not) it really doesn't matter.

In my opinion, the G5 will give you better service. Since you're going to be working with large images, purchasing a large external hard drive to store them might be a good option. Large USB 2 and Firewire drives have come down considerably in price.

Regards.

I second the G5, as it's got a faster clock speed, larger L2, and bus (all things which are important). Also it'll be supported for longer than a G4 might be, if you consider the future.

I don't see support for any of the PPC processors past leopard. From what I remember Snow Leopard is Intel only. So support would end for both the g4/G5 at the same time.

And finally I third the iMac. It may be easier to get an external firewire HD for expansion.

Definitely the G5!!!

I would recommend keeping the G5. Like he/she said above, only some applications benefit from dual processors. And just being an 867 mhz Dual. Nope. A single 1.6 G5 would blow that away. Some configurations of the 1.6 G5 will beat a 1.25ghz Dual G4, just depends. Sorry for the ramble; keep the G5!!!