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macrumors newbie
Original poster
Nov 21, 2005
23
0
San Jose, CA
Right now in my iMAC G5 I have 1.5 GB DDR SDRAM if I was to have all together 2 GB DDR SDRAM would that make any difference than what I have?? I have someone that has a extra GB. What should I do?
 

ksz

macrumors 68000
Oct 28, 2003
1,679
111
USA
It would be very hard to get a total of 2GB of RAM on the new iMac. This is because it has 512MB soldered on the motherboard and one empty expansion slot. You currently have a 1GB memory module installed in that slot, and you can replace it with a 2GB module for a total of 2.5GB.

But do you really need 2.5GB?

The answer depends on the types of applications you're running and the size and number of documents you are opening. For most people 1.5GB is more than enough. But you can check the real-time memory demands on your system by running "Activity Monitor" (use Spotlight to find it) and looking at the free memory indicator. If this is low or if you find that your system is significantly slowly down when you open and work with your documents and applications, it might be necessary to increase memory.

Remember also that operating systems use the hard drive to temporarily store parts of main memory to free up space. This feature has several names including disk paging, swap file/space, and virtual memory. The concept is very simple: Allocate main memory in 'pages' of a certain size such as 16K blocks (page size varies) and keep track of when each page is used. Least-used pages can be swapped out to disk, making new room available. However, even this system can be overloaded if there are no more least-used pages to be swapped out. In this case, the operating system finds itself in a very tight spot and it must continuously swap pages of memory to and from disk just to keep everything running. When this happens, your hard drive runs forever, it seems. This is called 'thrashing' and it's a sure sign for a memory upgrade.
 

CanadaRAM

macrumors G5
No, the original poster has the prior iMac G5 with DDR RAM, not the iMac (isight) model with DDR-2

The iMac (1.6, 1.8 or 2.0 DDR) machine has two memory sockets and no soldered on RAM. You can go from 1.5 Gb to 2 Gb by replacing the 512 Mb DIMM with a 1 Gb DIMM.

Whether this will be a performance increase for you depends mostly on the type of programs you are running and the number of programs you usually run at the same time. Heb (in another thread) reported significant speed gains going from 1 Gb to 2 Gb. If you are using Photoshop, video or sound editing software, or regularly have many programs open. you'll probably see an improvement, but not as dramatic as the improvement from 512 to 1.5 Gb was.

Thanks
Trevor
CanadaRAM.com
 

doucy2

macrumors 65816
Jul 7, 2005
1,013
0
my recomendation
add more ram as you can afford it
my sawtooth origianl 64mb now ive got 1.75gb (soon to be 2gb) the more ram the merrier
 

ksz

macrumors 68000
Oct 28, 2003
1,679
111
USA
Not really. CanadaRAM is correct: the upgrade from 512MB to 1.5GB is far more significant than a further incremental upgrade to 2GB. At this point you will get significantly diminishing returns with more memory. Whether or not an upgrade to 2GB or 2.5GB is worth it depends on the applications and documents you will be actively working with. Working with large movies (~45+ mins), RAW images, large JPEG/TIFF files, book-size documents or publications, etc. will impose more memory demands.

Adding more memory is not an automatic way to improve performance. The curve does not go straight up. Look at Activity Monitor to make a more informed decision.
 
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