best RAM configuration?

[jimedit1]

I have just ordered 4 x 1gb sticks for my mac pro (shipping).
I understand that there needs to be matching pairs to optimize the RAM.
Do I:
a) install a pair of 1gb sticks in each tray and split the 512 chips between the trays as well for a total of 5 GB.

b) put 4 gb in one tray and put the factory gig in the other for a total of 5GB

Or is there another option? Advice on this matter would be greatly appreciated.

 

[Digidesign]

You have

- 2x 512mb FBDIMMs for a total of 1GB
- 4x 1GB FBDIMMS for a total of 4GB

Correct?

If so, I think the following sums up your possibilities.

I'm still learning about the best and most optimal configs myself, so I'm curious what others have to say. AFAIK Possibility/configuration 1 is the most ideal because it is quad-channel and thus 256-bit? Others that are more knowledgeable please chime in.

 

[jimedit1]

a very clear reply.
Thanks!
Thats what i thought.

 

[Schroedinger]

Possibility 1 is the best way to go. With that set up you'll have 4 gigs at quad channel goodness. If you use possibility 2, you'll only have 2 gigs at quad channel goodness. The quad channel is limited to the smaller amount on either riser as the ram has to be matched (that is the pairs have to be matched to each other).