Confusion on Amount of RAM for 2007 Quad core

[tigress35]

I've got a quad core mac pro and I'm looking to put more RAM in than the originally shipped 1 gig (2 x 512). I've seen all the helpful links for what chips to put in which riser, however I've also seen people mention keeping things in multiples of 4 or 2.

I'm looking to put in 2 x 2 for 4 additional gigs, and keeping the original 1 gig. This would bring me up to 5 gigs total, but is it a bad idea to have 5 since that is an odd number? Or is it ok because it uses up 4 slots? 6 gigs might be a little more than I can presently afford/truly need. TIA!

 

[aaronw1986]

Odd is ok, you just must have pairs which you will. The thing with odd is that quad channel won't work, but it does not seem to offer much performance over dual.

 

[CanadaRAM]

That is fine. Put the 2 x 2 in Riser A, first two sockets, and the Apple RAM in Riser B first 2 sockets.

 

[tigress35]

Thanks! I think I read on another thread that a user suggested simply switching the risers, versus having to swamp the RAM. Is that ok to do?

And, if in the future I want to add another 4 gigs (2 x 2), for a total of 9 gigs, would that make it a "quad channel?" despite still being an odd number? I attempted to google this and couldn't find much that clearly explained the difference between a quad channel and dual channel.