View Full Version : 1 DIMM or 2 DIMM

Jul 19, 2003, 12:18 PM
im pretty nifty with my computer lingo...but...i seem to have a problem here...i know what a DIMM is im just wonder if there is a really a huge performance drop if u get 2 DIMMs instead of 1...

im speaking in terms of 512 RAM in a G4 1ghz powerbook (Ti)

Jul 19, 2003, 12:26 PM
i thought the powerbook only has room for 1 SOdimm??

Jul 19, 2003, 12:30 PM
Yes, there is a huge difference. Especially with a PowerBook.

The max RAM (stated by Apple) is 1 GB in you machine. Now, there are two ways to have 512 MB of RAM. One was is to fill both slots with 256 MB, leaving zero slots open. The other way is to get 512 on one chip, leaving the other slot open. What is the difference?

Next year, you want to upgrade. How do you do it? In the machine you have 2 256's in you must remove one before replacing it with a 512. Although you think you might get 1 GB in total, because you are adding 512 to your 512, you actually end up with 768 MB (512-256+512=768). How much sense does it make to buy a 512 MB chip only to upgrade your actual RAM by 256?

On the other hand, when you have 512 in one DIMM, upgrading is easy. All you do in snap in the new RAM, because you have 1 slot open.

So, my recommendation is to get the RAM in 1 DIMM for future expandability. Sure it will cost a little more (especially at the Apple Store!) but it is well worth it. At this point in time, with memory being so cheap, nobody should ever buy a DIMM less than 512 in my opinion.

Good luck.

Jul 19, 2003, 02:58 PM
There's not really a performance hit, but i definetly agree with getting a 1 DIMM of 512. You leave your expandability options open in the future, and if you go to resell 2 years down the road it might add to the value cause the buyer doesnt have to worry about buying a 512 dimm to gain 256 (512-the 256 in there).

Jul 19, 2003, 05:06 PM
On some newer PC's you gain performance by having two DIMMs vs one. These computers use Dual Channel DDR ram. They work with one, but with two they have a theoretical faster throughput. In practice there is a performance gain as well.

Jul 20, 2003, 02:32 AM
Originally posted by adamfilip
i thought the powerbook only has room for 1 SOdimm??

The 12" PowerBook, like the iBook maxes out at a smaller number MB RAM because there is a stick soldered to the logic board. The iBook maxes at 640, and the 12" PowerBook at 768 MB. The 17" and 15" do not have this problem, however.


Jul 20, 2003, 07:34 AM
Originally posted by Gus
... and the 12" PowerBook at 768 MB.
Gus Actually, the 12" PB is limited to 640MB of RAM as well. It comes with 256MB of RAM (128MB soldered to motherboard and 128MB in the slot)

Jul 20, 2003, 08:40 PM
Yes, my bad, thank you for the correction.