RAM allocation in Photoshop CS

[david_stensby]

I am running PS CS on a dual processor 2.5 gHz G5 MAC. I just

recently upped the RAM from 2.5 GB to 4.5GB and am disappointed that

there doesn't appear to be much difference in speed when working with

very large (200 MB) files in PS CS. The computer registers that it

has the 4.5 GB RAM, so it appears to be working OK. Do I need to

change the settings in CS? I've got 85% RAM allocated to CS. Is

there anything else that I need to do, or have I just reached the

speed limit of the machine?

[mona_chrome]

I know the old rule of thumb was 3 times the ram to the file size to get the optimal

performance. Of course, now with history and all, I am not sure if that still holds. My guess,

from what you are saying, is that you have just reached the max speed of the processors. I

have the dual 2.7, so am familiar with the equipment and I don't see anything else you would

need to do.

[nicholas_fiduccia]

You may be running into other limits imposed by PS CS itself

(Can PS CS handle more than 2MB?) or by OS-X. Which

operating system are you using?

[mona_chrome]

I just thought of one thing, have you built up your RAM symmetrically. I do believe that you

have to do that. If you have added it yourself, just call your local MAC dealer to be sure you

have it all in there right.

[dan_n1]

RAM limit setting in PS CS is 2GB, in PS CS2 is 4GB

[david_stensby]

Thanks for the quick responses. To answer several questions: Yes, I built the RAM symetrically. I think it's installed properly. I am using OSX 10.3.9. Perhaps the last post is the answer - CS can only use 2 GB ram and that's what I had before (2.5 x .85 = 2.125). Am I correct that to increase the speed I would have to upgrade to CS2?

[dan_n1]

Since you have 4.5Gb of ram, it's a good idea to upgrade to PS CS2 but don't give 100%

ram allocation because you will have only half a gig left...A 2nd hard drive as scratch disk

will improve the speed too, best choice is a fast (10.000rpm) SATA and leave it empty,

put nothing in it. I put 4 hard drive in my G5, but it's another story (anyone want to know

how to do it, I will post the link)

[bobmichaels]

I tried to find a workaround to use more than 2Gb of RAM with CS using XP. I never found one but maybe there is some Mac difference. After upgrading to CS2, I realized there are several good new features in CS2.

 

It's time for the CS2 upgrade.

[godfrey]

An upgrade to CS2 would help but only a little bit. What would help more is to install a

second, fast SATA hard drive and set Photoshop CS2 to use it as a scratch volume. Even

that will only help so much ... there comes a point where the bottlenecks are simply

processor speed and IO, not how much RAM or how big a disk you've got.

 

I run a G5 2G DP set up with 3G RAM and second scratch drive as above. I've got CS2 set

to use 70% of RAM (2G) and six cache levels. The speed in handling 250-300M image files

is quite good, far as I can tell. I'm not sure how much better it will get when I add another

2G of RAM as it seems more IO bound than anything else.

 

Godfrey