"All Intel Core Macs will run with mismatched RAM, at the loss of the dual channel speedup. These Macs can run a 3 GB configuration (1 GB + 2 GB), which on average can be faster than a 2 GB matched pair if you are using heavy programs like Photoshop that can benefit from the extra 1 GB"
I got the above from a website....so does that mean that if you have mismatched ram it just barely runs as fast as a lower amount of ram but that ram is a matched pair?
If you look higher on that page it says that Dual Channel gives an average 6% - 8% speed up.
So if you go mis-matched, then you lose 6% to 8%. But then *depending on the programs you are running* having the extra 1 Gb RAM may more than make up the loss.
If you only use less than 2 Gb of program and data RAM, then it'll be a bit slower, because you wouldn;t be leveraging the 3 Gb.
But the times when your programs and RAM exceed 2 Gb, the machine could be quite a lot faster, because you are avoiding PageOuts to the hard drive.
Is the restriction of 3GB on former iMac because of hardware?
Can't they unlock it to 4GB with firmware update?
Y'know, I thought I saw someone link to the
earlier in this thread, maybe even twice....
Seriously, please read the thread, people -- the answers have been given -- much as I like repeating myself, this is the 20th time I have posted the same info.
everyone considering getting ram NEEDS to do this: Get iStat pro in your dashboard, run the computer for a day or two with normal usage, and look at your page in/outs. You'll always have alot of page ins, but pages outs, how many do you have?
If after a few days of use you have gathered up a few 10k outs, you are probably low on ram. If it's a few hundred, you are probably fine.
My iMac with 1GB got about 300,000 outs in just 1 night of work... def needed more. My Mac Pro with 5GB has 2.7 million ins and zero outs... so I haven't hit my disk in nearly a week.
Good advice Sean: Couple of things: You don't need iStat, the same PageIn/Out information is in the Activity Monitor: System Memory.
The number of PageOuts isn't as significant as the ratio of PageIns to PageOuts. You are ideally looking for a 20:1 ratio (PageOuts at 5% of Ins, or less). If you start exceeding 10%, that means it is time for more physical RAM and/or reducing multitasking, background processes and (ahem) Dashboard Widgets.