The PowerEdge 840 has a max of 8GB, as limited by the Intel 3000 chipset.  No BIOS update will change that.
Hi There In the tech spec it says the max memory on a poweredge 840 is only 8GB. Do you know if this is still the case, IE can I install more with the aid of an bois update or similar? Thanks  
Poweredge 840 memory upgrade past 8GB