mac pro mix match memory config

[jefc]

I have a new macpro that came with 2g ram (2x1)
I bought additional 4x2g ram...
Can I keep the originall 2x1 and combine them with the new ones for a total of 10g ram and use the original 2g to run parallels?
Thanks:) Happy Thanksgiving!

[Tallest Skil]

You can't really relegate RAM like that, but keep it all.

Riser A: 2GB 2GB 1GB 1GB
Riser B: 2GB 2GB xxx xxx