My 3gig quandry

[Kramer]

so. i am at the Apple store, talking with someone about their laptops. we are discussing the difference in Ram btwn macs and pc's, of course i am quite clear that amount of ram doesn't necessarily matter when considering the whole of the machine you put together.

but the Apple guy can't help and begin a rant about pc's, and he mentions something that i found odd... he said that with an odd numbered amount of ram (3g or 5g when your machine can hold 4 or 8g) it causes a "bottleneck" effect and the RAM will end up being less efficient/runing slower

so what's the deal?

[vonkaar]

He's basically an idiot.

I mean, Genius. In the Apple world.

Hell, the last version of the Macbook (rev.B) shipped with 3Gb of memory...

[vonkaar]

To expand on my idiot comment...

Earlier versions of the macbook supported asynchronous dual channel mode, like almost every modern PC. This allowed the macbooks to run mixed sizes (2Gb & 1Gb, for example) and still run in dual channel. The performance difference between synchronous and asynchronous dual channel is almost nil, but dropping out of dual channel altogether is a 'big' hit. Most modern notebook chipsets allow you to mix and match ram sizes so you can 'stay' in Dual Channel. Same size = synchronous dual channel. Mixed sizes = asynchronous dual channel. Theoretically, asynchronous is a slight performance hit, but even ridiculously robust CPU/Memory stress utilities hardly notice the difference.

Basically... Apple removed the ability to be flexible, which shouldn't surprise you. If you mix memory sizes, you drop into single channel mode - which IS a giant performance hit. But in a PC, this isn't the case. You can swap between synchronous and asynchronous mode all you want. Apple, you get 1 choice.

Those 'geniuses' are taught Apple propaganda, but not much else.

[Kramer]

danka sir. sounded a bit odd.