Hello, I'm Jewel with Kingston Technical Support. The Gigabyte GA-EX58-UD3R is not listed in our Memory Search since we no longer support this motherboard. If you go to the Discontinued Parts search you can find it and find discontined parts that would be compatible with it. Our HyperX Fury memory is not compatible with your motherboard since it does not support High Density or Single Rank 4GB memory modules. All of our currently manufactured 4GB desktop memory modules are high density and would not work properly in your motherboard. You can check our discontinued memory search for compatible part numbers that may still be available from some resellers, found here...