CPUz only tells you about the chip and how much ram you have. Not very useful here.
Do this>
Get Everest at this link and scan the system> http://www.lavalys.com/products/download.php?pid=1&lang=en
It's free by the way.
Now armed with what type of ram and the true make and model go to this website and follow the directions to find how much your system can handle> http://corsairmemory.com/corsair/configurator_search.html
If it's out there those folks will have it.