[X4U] Do you REALLY need matching memory in a Mini?

[Philip J Robar]

On Aug 25, 2006, at 4:27 AM, David R. Boag wrote:

> Just received my Mini Duo 1.66GHz/100GB that I had upgraded from  
> 512 MB RAM by taking out one of the 256 MB DIMMs and replacing it  
> with a 1 GB. My dealer (20 years of mac experience) says it's  
> really not much of an issue. Is it?

First your Mini Duo definitely uses memory interleaving: http:// 
tinyurl.com/gaq8f
(http://developer.apple.com/documentation/HardwareDrivers/Conceptual/ 
HWTech_RAM/Articles/RAM_implementation.html#//apple_ref/doc/uid/ 
TP40003899-DontLinkElementID_16)

The short answer is that you probably don't care as the difference  
between interleaved and non-interleaved performance is below human  
perception.

As to how big a deal it is, it really depends on the application. If  
it's I/O bound then it won't help, but if it's a big memory user then  
the difference can be measured. Articles on 68K and early PowerPC  
Macs found a range of 1 to 22%, with Apple claiming an average of 8%  
leaving out apps. that didn't benefit. (Google: memory interleaved gain)

I personally would have gone for 2 x 512 MB and sold both 256's to  
cover some of the cost. But, it you're a Photoshop or similar user  
then get a second 1 GB DIMM and be happy - memory is cheap these  
days. (http://www.dealram.com is a good place to check prices.)


Phil