10-30-2007, 02:51 PM

Yo every one...quick question..I think I know the answer but want to double check with you guys. I have a macbook pro 15 inch 2.16 with 1 gig of ram, my friend bought a new macbook pro 15 inch 2.4, he took his stock ram out 2 gig and got new 4 gig ram, can I use his old 2 gig ram, are they the same, from the apple site they look the same. also can i mix the ram. My mac is max at 3 gig, can I use 1 gig sim, plus his 2 gig sim, to make it 3 gig, or do the ram have to be in pair.

10-30-2007, 03:56 PM

Since your computer uses "dual channel memory", it's usaully better to keep your ram paired (i.e. 2x1 GB sticks), it results in a more efficient use of ram.

If you install 4 gigs of ram and look at your "about this mac" it will say 4 gigs, but if you look at your activity monitor, it'll only say 3 gigs. so thats why the limit is 3 gigs.

Basically, it might not work any better than it does now, but go for it! let me know if it works better.

10-30-2007, 07:06 PM

Knee said that he has 1 MBP with 2.16 processor so maximum ram can be installed is 3GB .You can mix ram between your friend's ram with your ram .And because those ram are from Apple so your laptop will run well .
Enjoy it ^^

10-30-2007, 08:07 PM

HaHa finaly got the ram...and all I have to say is Booooo my friend drop off the ram....Boooo they are 2 gig haha but 2 sims of oem ram from his macbook pro, there samsung ram....he upgraded to 4 gig of ram, so he gave me his old ram...i guess instead of 3 gig i'll be using 2 gig..haha...i I look at the bright side of things...at least there free...hehe

10-30-2007, 09:22 PM

2x1gigs=better performance than 1gig+2 gig!

10-31-2007, 01:10 AM

KNEE: You can mix the RAM, yes. However, your machine probably has 2 512MB sticks installed. If that's the case, you're going to be better off running the 2 1GB sticks (obviously).

MacBookie... to put it bluntly: you're wrong (see definiton #2. Also see synonyms inaccurate, incorrect, and mistaken).

Yes, running in dual channel will double the RAM bandwidth (Well, on paper. It's not quite that simple, but for our purposes, it's close enough). Thing is, it makes no difference on the older (non-SR) MBPs. Why? The CPU in the older MBPs has a 64 bit wide, 667MHz bus. Which will transfer data at the same rate as a *single* 667MHz, 64 bit DIMM.

In other words: Except for the latest SR-based MBPs, running dual channel RAM on the MBP nets you an increase of, near-as-makes-no-difference, bupkis. You can take my word for it, if you like, or you can check Anand's tests here (scroll down to where it says 'page 4'):
http://www.anandtech.com/printarticle.aspx?i=2740

You might be able to measure a very small (<5%, tops) increase in performance in synthetic benchmarks (e.g. SiSoft Sandra in Windows) by running 2GB in dual channel vs. 2GB in single channel. But 3GB in single channel is going to be *significantly* faster in every real-world scenario on an older MBP, and in almost every case on the SR MBPs, too.

And besides... There's a good chance that the i945m in the older MBPs (and the i965m in the SR machines) supports asymmetric dual channel mode. In other words, if you have say, a 1GB stick in one slot and a 2GB stick in the other, it will run in dual-channel mode while it is accessing the first 2GB of RAM, then drop to single channel for the final gig. I'm not 100% certain of that, but that's what I and a buddy of mine (who spends more time obsessing over Intel mobile chipsets than I do) recall.

10-31-2007, 04:53 AM

To Macbookie '2x1gigs=better performance than 1gig+2 gig!' I am wondering why 2gb can run better than 3 gb ? can u explain for me ? because one of my friends use MBP 2.33 and he use 3gb and it 's much faster than I expected .