Question How to get my hardware (i5-750, p55-ud3l) to have more ram?

[dakiz]

I'm currently using 2x4gb kingmax ddr3 1333. I need 4 or 8gb more ram
It's an ancient setup so there are all kinds of compatibility issues

 

[JohnBonhamsGhost]

buy a 16GB DDR3 RAM kit.

 

[Nirmith Akash Anawarathne]

According to the gigabyte support information rev 1.0 of your model can do 1600MHz 8GB so you will be fine. but the problem is if you mix them with what you have now it will reduce the speed of new RAMs to match the others. If you're not considering speed then go for 1600 8GB or else buy a kit of 16GB with more speed.
It can only support up to 16GB but not more than 2200MHz

 

[dakiz]

According to the gigabyte support information rev 1.0 of your model can do 1600MHz 8GB so you will be fine. but the problem is if you mix them with what you have now it will reduce the speed of new RAMs to match the others. If you're not considering speed then go for 1600 8GB or else buy a kit of 16GB with more speed.
It can only support up to 16GB but not more than 2200MHz

Can it run with three slots inserted (4-4-8)? or four slots (4-4-4-4)?

 

[Nirmith Akash Anawarathne]

Can it run with three slots inserted (4-4-8)? or four slots (4-4-4-4)?

Yes you will be fine but make sure that two 4G sticks are on the same channel (A channel means two same color sockets on a 4 socket motherboard). Sometimes on old motherboards when you plug sticks with two different speeds into a single channel... they provide boot errors. But (4,8,4,0|1,2,3,4) will be fine.

 

[SkyNetRising]

P55-ud3l boaard supports 16GB max. 4 slots 4GB each.
It may not support 8GB ram modules.

 

[logainofhades]

That board probably will not support 8gb modules. Try to get a matching 2x4gb kit to the ram you already have. Otherwise, you will need to get a 4x4gb kit, to get 16gb.