What's the best Mac for Photoshop?

Question

I daily work on layered photoshop files, up to 10 (ten) GB. I currently have a G5 with 8 gb of ram. I finally can afford to upgrade to a faster computer and need to figure out if the 8core 2.93GHZ at $5,899 is the best buy for me. The 8 core 2.26GHZ is $3299. For an additional $2500 I would need to know that I will get at least 15% increase in speed. I remember back in the day when I picked out the fastest g5, when I later compared it to a slower G5, the difference in speed was barely noticeable, and when I upgraded to 8GB of RAM I discovered that photoshop could only take advantage of 2 GB.
Does photoshop benefit from 8core vs 4 core?
Will an 8 core 2.26ghz be faster than a 4 core 2.93GHZ when working in photoshop?
Is there something new coming out, so I would benefit from waiting with my purchase?

Answer 1

I work on big files, tho not that big.
For many of the time-critical things I do in Photoshop seem to be single-processor, so even tho I have an 8-core machine, often only one is being used. This includes things like flatening and saving. So I am not sure that (unless you have other programs running) you would ever see an advantage to more than 4 cores.
What I do notice when I work with big files, is that I keep a copy of Activity Monitor open, and whenever the green sector in memory goes to zero, my computer becomes unusably slow, and I usually reboot. I don't understand memory managment on the Mac, but whatever "inactive" means, it really means "swap yourself to death". So I have 14GB of RAM on my computer, and I usually don't run out even when dealing with big files. But I know that 8GB would not have been enough. Photoshop may not use more than 2GB, but it and the OS can cache materials and when those caches get too big, my computer comes to a halt. With your files, you may find 32GB to be useful.
What I have done is to burn a CD or DVD with one big psd/psb file and walk down to my local Apple Store. The machines there don't have much RAM, but you can get some feeling for 4 cores vs. 8 cores. Reboot them before you do anything.
One thing I would strongly recommend you do not try is what I did with my old G5--install a RAID. It only increased opportunities for losing files, and while it certainly sped up many file operations, I don't think any Photoshop operations were affected at all.
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