Hello and welcome to PC Help Forum.
Some PCI cards use part of the
RAM so your
RAM seems to appear lower than what is fitted.
The use like this either 32,64,128,256 of
RAM,It is dedicated to use with say your graphics card and this can also be set in BIOS how much can be dedicated to another device.
A conflict can occur when you fit a new graphics card,there for you turn off onboard graphics card in BIOS to allow new one to run correctly.
Did you install new drivers for the new card?
Have you turned on onboard graphics card in BIOS so you can use it?
You seem to of not setup BIOS correctly to run the new cards nore dedicated
RAM correctly your card may need to use at least 128 of your
RAM to function correctly.