Just doubled my iMac's ram... no performance gain in CS3
by Arvin Bautista
on
Jul 22, 2008 at 5:09:52 am
Just got myself a new aluminum iMac with 2.8 ghz core 2 duo with 2gb ram. I ran a benchmark on a simple but hefty CS3 project (an andrew kramer project file) with multiprocessing, and it finished in 3:30 minutes. (With no multiprocessing it was running at around 4:50)
Today I just doubled the ram successfully, and tried to tweak the memory settings to take advantage, and a few issues came up. First of all, CS3 is only detecting 3 gigs (100% mem. usage shows as 3 gb). Secondly, no change at all in the benchmark time, still 3:30.
Here are the memory and cache settings right now, with the 4 gigs installed:
Max mem. usage: 100% = 3.0 gb
Max RAM Cache: 50% = 1.5 gb
Disk Cache Disabled.
PLEASE would really appreciate as many tips as possible to prove to me that I didn't buy that extra ram (and now have to figure out how to sell the original ram) for no reason.
Re: Just doubled my iMac's ram... no performance gain in CS3 by david bogie on Jul 22, 2008 at 3:25:58 pm
I think that's all CS3 can see in its present rev: 3 gigs. that shoudl change with updates or CS4 which is also supposed to be Intel-savvy and Leopard-ready.
RAM rarely does anything significant to improve processing of AE's video pixels. You really only gain procesing speed by speeding up your processor. Future revs may take advantage of the GPU but you can't change the graphics card on your iMac, can you?
Where you get the impression RAM would help?
bogiesan
This is my standard sigfile so do not take it personally: "For crying out loud, read the freakin' manual."
Re: Just doubled my iMac's ram... no performance gain in CS3 by Kevin Camp on Jul 22, 2008 at 3:43:23 pm
you can try increasing your max ram cache to the default 60%, you have plenty of ram for a 2-core machine.
i believe the only time you'd see a performance gain with more ram would be when you were rendering comps that were hitting the max ram cache ceiling. the ram cache is where ae stores its cached frames. it can then call on those frames as needed (for things like motion blur and time effects) rather than having to render them over and over just to create something like motion blur. so, if the comp was hitting the max ram cache limit, adding more ram would allow it to cache more frames and that may increase render speed. if it was only getting to 30%, then you wouldn't see much of any difference.
also, having more ram available that is not part of the ram cache (by adding ram or lowering the max ram cache) will give you more space for ram previews (so, longer previews) and more space for image buffers, if you ever get image buffer errors... so you can benefit from your ram that way too....
Re: Just doubled my iMac's ram... no performance gain in CS3 by Chris Wright on Jul 22, 2008 at 8:17:39 pm
if you enable disk cache, the rendering time will be cut in half. It will retain places you cached while viewing. All those little green lines will stay there and be used to render output so the computer won't have to start from scratch. The downside is you would want a fast separate hard drive or interaction will be sluggish.
Re: Just doubled my iMac's ram... no performance gain in CS3 by david bogie on Jul 22, 2008 at 9:03:41 pm
[Chris Wright]"f you enable disk cache, the rendering time will be cut in half. It will retain places you cached while viewing. All those little green lines will stay there and be used to render output so the computer won't have to start from scratch. The downside is you would want a fast separate hard drive or interaction will be sluggish."
This assumes viewing while editing matches the render settings. Mine rarely do in order to speed up editing.
bogiesan
This is my standard sigfile so do not take it personally: "For crying out loud, read the freakin' manual."
I could be wrong, but with multiprocessing don't you want you max mem. usage to be hitting at about 1 gb? I would try lowering that amount until that number gets down to 1. about 40% or so.
Joey
