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hoopster

macrumors member
Original poster
Apr 17, 2010
45
0
I am about to upgrade my late 2008 aluminum MacBook 2.4 Ghz to 6GB of ram from owc but wanted to know if the will support 8GB, running at full stability. From what I can tell from other threads is that the owc 8GB kit doesn't work is this correct? If it can handle 8GB of ram I will do that instead of 6GB. Thanks for any help.
 

jav6454

macrumors Core
Nov 14, 2007
22,303
6,257
1 Geostationary Tower Plaza
6 GB still has more of a performance boost than 4 GB w/ dual channel. IIRC, dual channel has a fairly small boost anyway (something like 10%).

Yeaaa....NO

Single channel is half the current speed. Currently, 17.1GB/s is the speed of dual channel DDR3-1066 memory. Single channel would be half of that. A greatly appreciated performance drop.
 

iThinkergoiMac

macrumors 68030
Jan 20, 2010
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Terra
That's my opinion. Unfortunately, I can't speak from experience since I went directly from 2 GB to 6 GB on my own MacBook, so I can't compare to 4 GB. But research online suggests that dual channel mode, while beneficial, doesn't have much of a performance boost unless you're moving lots of large blocks of data (4 MB or more), which would only happen if you're doing a lot of mathematical applications.
 

jav6454

macrumors Core
Nov 14, 2007
22,303
6,257
1 Geostationary Tower Plaza
That's my opinion. Unfortunately, I can't speak from experience since I went directly from 2 GB to 6 GB on my own MacBook, so I can't compare to 4 GB. But research online suggests that dual channel mode, while beneficial, doesn't have much of a performance boost unless you're moving lots of large blocks of data (4 MB or more), which would only happen if you're doing a lot of mathematical applications.

Or using RAM heavy tasks... just using Safari is using 400MB while browsing MR, imagine using Flash...
 

dukebound85

macrumors Core
Jul 17, 2005
19,131
4,110
5045 feet above sea level
Yeaaa....NO

Single channel is half the current speed. Currently, 17.1GB/s is the speed of dual channel DDR3-1066 memory. Single channel would be half of that. A greatly appreciated performance drop.

Everything I have read is that dual channel nets about a 10% increase in performance and more ram usually wins out over having less ram running in dual channel
 

iThinkergoiMac

macrumors 68030
Jan 20, 2010
2,664
4
Terra
Yeaaa....NO

Single channel is half the current speed. Currently, 17.1GB/s is the speed of dual channel DDR3-1066 memory. Single channel would be half of that. A greatly appreciated performance drop.

In theory, you're correct. In application, you're not. What dukebound said is correct. Apart from very specific tasks that benefit greatly from dual-channel mode (that very few users do), dual-channel is a small side benefit, but not as much of a benefit as more RAM.
 

hoopster

macrumors member
Original poster
Apr 17, 2010
45
0
So will I benefit greater from 4 or 6GBs of RAM? I do use a lot of memory intensive apps.
 

dukebound85

macrumors Core
Jul 17, 2005
19,131
4,110
5045 feet above sea level
So will I benefit greater from 4 or 6GBs of RAM? I do use a lot of memory intensive apps.

the solution is obvious

get 2 3gig sticks haha

But in all seriousness, you will see an improvment regardless of what you do. What I would do is this

Get one 4 gig stick

Then see if it is faster by itself or see if that 4 gig stick and one of your old ones (for a total of 5gigs) is better for your needs. If more ram is better, get a 2 gig stick to compliment the 4gig or just stay at 5gigs

regardless, I would at least get a 4gig stick
 

hoopster

macrumors member
Original poster
Apr 17, 2010
45
0
the solution is obvious

get 2 3gig sticks haha

But in all seriousness, you will see an improvment regardless of what you do. What I would do is this

Get one 4 gig stick

Then see if it is faster by itself or see if that 4 gig stick and one of your old ones (for a total of 5gigs) is better for your needs. If more ram is better, get a 2 gig stick to compliment the 4gig or just stay at 5gigs

regardless, I would at least get a 4gig stick
The only problem with that is that dual channel requires 2 sticks. So I'm still not getting dual channel with one 4gig stick so 6gigs will be faster than that
 

iThinkergoiMac

macrumors 68030
Jan 20, 2010
2,664
4
Terra
The only problem with that is that dual channel requires 2 sticks. So I'm still not getting dual channel with one 4gig stick so 6gigs will be faster than that

Dual channel requires a matched pair (1+1, 2+2). Your RAM is in dual channel mode right now (assuming you have 2x 1 GB sticks).

6 GB would be the fastest. That's a lot of RAM, and if you don't think you'll need 6 GB, then just get 2x 2 GB sticks for 4 GB in dual channel mode.

Don't let dual channel mode be part of your decision. Figure out how much RAM you want/need. If you can get it in a matched pair, great. If not, no biggie.
 

hoopster

macrumors member
Original poster
Apr 17, 2010
45
0
I will have to think about which one I'll do. I'm leaning towards 6GBs because I plan on keeping this computer for another 3-4 years and think that in 3 years 4 gigs isn't going to be enough. Plus I plan on getting a SSD in the fairly near future and really don't want to overflow onto that at all for VM. Thanks for all your help.
 

modest serving

macrumors member
Feb 16, 2010
34
0
I know this is an old thread, but I'm pretty sure you can go all the way to 8GB or RAM in snow leopard and lion on the 2008 Unibody Macbook
 

Henkali

macrumors newbie
Jan 14, 2010
1
0
I know this is an old thread, but I'm pretty sure you can go all the way to 8GB or RAM in snow leopard and lion on the 2008 Unibody Macbook

I read that Snow Leopard (or newer) and Bootloader version MB51.007D.B03 (or newer) would give support for 8GB RAM.
I just bought two Kingston 1333MHz 4GB modules and my Macbook with Lion seems to be working OK. Surely I cannot tell about stability at this point as this has been ON only for hour or two, but anyway, all 8GB are available and visible to OS.

I took 1333MHz only because it was cheaper than 1066MHz :)

I think I won't sell my old memory yet, I'll give this 8GB few weeks to see if computer stays stable.
 

Tony L

macrumors newbie
Jul 24, 2011
4
0
I'm running 8GB in a late 2008 unibody MacBook under Lion and it works a treat. I went from the standard 2GB and it was a very worthwhile upgrade, just much faster and no churning of the HD. I used Kingston RAM from Amazon - as it's so cheap I thought I'd go for a known brand with good warranty.
 
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