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

[Stroller]

On 25 Aug 2006, at 12:27, David R. Boag wrote:

> Just received my Mini Duo 1.66GHz/100GB that I had upgraded from  
> 512 MB RAM by taking out one fo 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?

The Mac Mini appears to support dual-channel operation, which does  
indeed seem to be the same as "interleaving". "Dual-channel" is the  
current terminology applied to modern PCs of the last two to three  
years, however when I looked up interleaving on Macs I found it  
referred to machines manufactured in 1999! So Macs appear to be way  
ahead in this department!!

Whilst dual-channel operation (usually requiring matched pairs of  
memory) doubles the memory bandwidth, this is not the machine's only  
bottleneck, so the performance benefit may be in the order of 10% or  
less. I find the performance / benchmark charts in <http:// 
www.kingston.com/newtech/MKF_520DDRwhitepaper.pdf> to be unhelpful  
(if not wilfully misleading), as they don't compare (say) 512meg  
single-channel against 2 x 256meg dual-channel. Indeed the only  
conclusions I can take from that paper are that "more RAM is faster",  
"faster RAM is faster" and that "doubling the amount of RAM doesn't  
double the machine's speed" (but in dual-channel configuration under  
the best of circumstances it may nearly do so, which is significant  
assuming this performance gain is achieved on otherwise identical  
systems).

In summary, your dealer seems to be right.

Personally, if I were upgrading the Mini (and as I intend to upgrade  
my current 13" MacBook) I would stick 2 x 1gig sticks of RAM in  
there. IMO if you're bothering to upgrade RAM is cheap these days and  
you might as well have top performance.

But certainly your current configuration is better than had you  
chosen to upgrade to 2 x 512meg RAM. 1.25gig single-channel will  
probably give better performance than 1gig (2 x 512meg) dual-channel  
and you're in a better position to consider upgrading to 2gig in the  
future.

My only caveat in this is graphics performance. Since Mac Minis &  
regular MacBooks have on-board graphics which share the system RAM,  
single-channel may be a bottle-neck. A 10% gain in this area may be  
far more apparent than in the start-up time of Mail.app.

Stroller.