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samb

macrumors newbie
Original poster
Jan 20, 2006
14
0
have 512mb in my macbok pro at the moment.

was going to get another 1gb memory upgrade.

but i have just read this "you should install in identical pairs (preferably in kits) for optimal performance"

is it ok to install 1gb in one slot and leave 512mb in other, or will it cause problems????
 

prostuff1

macrumors 65816
Jul 29, 2005
1,482
18
Don't step into the kawoosh...
samb said:
have 512mb in my macbok pro at the moment.

was going to get another 1gb memory upgrade.

but i have just read this "you should install in identical pairs (preferably in kits) for optimal performance"

is it ok to install 1gb in one slot and leave 512mb in other, or will it cause problems????

It should not cause any problems. The reason apple says in pairs is because the ram can run in dual channel. The difference between matched and unmatched will be so little you will probably not even notice.
 

RainForRent

macrumors 6502
May 31, 2006
291
3
Greenville, SC
The best thing to do is to put the 1 GB stick in the first (bottom) slot.
When the computer reads memory,
think of it as a water jug-
you want the biggest one to fill up first since it has more room,
then any overflow is for the smaller one.
When that overflow occurs is when performance suffers a minute amount,
so having the larger stick used first reduces that.

At least,
that is the way that I had it explained to me years back. :)

Hope it helps.
I have this same setup in my MBP.
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,390
2,829
PowerMike G5 said:
1.5GB will run fine in your MBP. But yes, you will need to identical-sized RAM sticks for your notebook to run in dual channel mode.

Keep in mind that it's more than just size that matters...all specs must be identical, even the specs you can't find anywhere. Which is why it's best to buy two sticks at the same time or a two-piece kit.

That said, the MBP doesn't see all that much of a speed benefit by running matched RAM...it's much more important for machines with integrated graphics like the MB and the mini.
 

dwd3885

macrumors 68020
Dec 10, 2004
2,131
148
so how much will a jump to 1.5 gigs improve system performance on a Macbook Pro that has 512mb Ram? I'm considering doing the same thing. (just buying a gig to equal 1.5)
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,390
2,829
You'll likely see a pretty significant boost in performance. It depends on what applications you use and how many at one time (and in what combination and what you do with them), but unless you only use it for web browsing and iTunes, you'll see a good bump.
 

TaylorB

macrumors regular
Oct 13, 2006
216
1
So you can use different size sticks, and you will not be able to take advantage of "dual channeling." But from that last post, it doesn't seem like that does much anyways. I just want this to be answered.. Is it safe for you to add on a 1GB RAM stick to your 512mb (512 is already installed, from apple.) I just need to put the 1GB stick below the 512mb?
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,390
2,829
You can absolutely add a 1 GB stick to the existing 512 MB stick. I don't think it really matters which one goes in which slot.
 

miles01110

macrumors Core
Jul 24, 2006
19,260
36
The Ivory Tower (I'm not coming down)
WildCowboy said:
You can absolutely add a 1 GB stick to the existing 512 MB stick. I don't think it really matters which one goes in which slot.

Correct- the computer doesn't differentiate between which slot is "up" and which is "down."

Dual channeling does have it's advantages, but in your case you are tripling your memory capacity. The speed boost you'll get from increasing the amount of RAM is much greater than that you'll get if you were to dual channel.
 

TaylorB

macrumors regular
Oct 13, 2006
216
1
Now i'm confused again. I was just told that 512 mb is built in and MacBook Pro users have two extra EMPTY slots. Since I don't have the right tools to open mine up, would someone midn to tell me if the standard 512 mb is in one of the two slots, or is the 512 mb already built into the computer? Someone please help! Thank you so much! :)
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,390
2,829
MacBook Pros have two user-accessible RAM slots...that's it. The entry-level model has a single stick of 512 MB in one slot, while the second slot is empty.
 

CanadaRAM

macrumors G5
TaylorB said:
Now i'm confused again. I was just told that 512 mb is built in and MacBook Pro users have two extra EMPTY slots. Since I don't have the right tools to open mine up, would someone midn to tell me if the standard 512 mb is in one of the two slots, or is the 512 mb already built into the computer? Someone please help! Thank you so much! :)

You don't need tools - go to the Apple menu and select System Profiler. Under "Memory" it will tell you what is installed in each socket.


(BTW You was told wrong. Don't take any horseracing tips from that source, either)
 

TaylorB

macrumors regular
Oct 13, 2006
216
1
Okay, awesome. Thank both of you guys. (sorry, I'm still new to Macs, but I help when I know whats going on!) Thanks again. :)
 
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