X8440 Server Module with 64-Gbyte or greater memory configuration is experiencing performance issues. (CR 6580544, CR 6580044, CR 6406979)
Update RHEL AS 4-U3 to RHEL AS 4-U4.
OR
Enter AMI BIOS and disable the memory hole option by performing these steps:
Press F4 to enter Expert mode.
Disable the Memory Hole Remapping option:
=>Chipset =>Northbridge =>Memory Configuration => Memory Hole Remapping = Disabled.
Press F10 to save changes.