In my PC currently I have 2/4 slots being used on my motherboard. The ones in use are https://www.amazon.com/2x4GB-HMT451U6AFR8C-PB-PC3-12800U-Desktop-Memory/dp/B01E96S1DI these, which is 2x4GB FBDIMM RAM. I am looking to upgrade and use the other slots and buy another 2x4GB of UDIMM RAM and I was wondering if it is possible to use UDIMM RAM in addition to the FBDIMM RAM.