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Anybody have 1.25GB RAM on MacBook?

TBi said:
Those tests aren't fair. Of course you'll get better performance with 2GB ram than with 1.25GB ram. They should have kept the memory around the same size, comparing 2x512 Vs 1GB + 512.

Now the question remains is the performance hit due to the lack of ram or due to dual channel.
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I have a hard time using 1GB of ram with a single application open so I doubt the difference between 1.25gb and 2gb is going to affect the test that much.

Either way it proves that a) Matched pairs do perform substantially better for some tasks ( and no worse than unmatched for others ) and b) the built in graphics are a far cry from the lowest non-integrated solution on Apple.
 
Intel makes it quite hard to find info about the "flex memory" tech--this is a quick summary though: a beyond3d review of an older desktop board
Flex has three modes of operation:
Single-Channel
Only one of the memory channel is populated
Dual-Channel Asymmetric
Different quantities of memory can be placed in each channel. eg: Channel A 1x256MB DIMM + Channel B 1x512MB DIMM, or Channel A 2x256MB DIMM's + Channel B 1x256MB DIMM
Dual-Channel Symmetric
Operates in full performance Dual Channel mode when memory configurations of the same memory quantities are in both channels. eg: Channel A 2x256MB DIMM's + Channel B 1x512MB DIMM, or Channel A 2x256MB DIMM's + Channel B 1x256MB DIMM, or Channel A 2x512MB DIMM's + Channel B 2x512MB DIMM's
The maximum performance should be enabled when Dual-Channel Symmetric memory is in operation, however the Asymmetric mode enables Dual-Channel bandwidth at slightly reduced performance.
Click to expand...

And I found this Intel whitepaper that gives full details. Basically, with asymmetric ("mis-matched") pairs, you get dual-channel operation only to the top of the smaller channel. I think this means that (in the case of this thread), you get dual-channel performance while accessing the first 512MB. The next 768 will be at single-channel speed.

So none of us were entirely right, but I learned something new. And it still stands that if you want the best performance, get 2GB!
 
Props to everyone finding the Intel Flex Memory whitepapers. I've been looking for them again for sometime.
 
Yup good work finding that data. Stands to reason though, but it's only obvious when you know it.
 
I've just ordered 1GB RAM from Crucial to run alongside one of my 256MB modules in my MacBook. I'm sure I will see a significant speed increase regardless of wether it runs in dual channel or not.
 
Well, I just got and installed my gig of RAM from Crucial alongside the stock 256MB module. So far, I can't say I notice a huge boost in performance, but I have tried running Logic or anything resource hungry.
 
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