System reports 8GB(3.99GB usable) at 64bit OS with 8GB(2GB*4pcs)memory installed. And "Memory Remap Feature" is "enabled" under Advance Chipset of BIOS.
Please make sure that you exact follow the instruction of the manual for plugging the memory modules in order first as defined by Intel.
The possible reasons may cause the memory size half reduction are,
1. Memory Remap Feature need to be enabled for 64bit OS.
2. Memory module not well installed on DIMM slot.
I got "no display" when installing the Intel Core i5-760 on my H57H-M/V1.0A MB. What's wrong?
Since the Intel Core i5-760 does not come with "Integrated Graphics", you must insert a PCI-E VGA card on the H57H-M/V1.0A MB with this CPU to get the display.
For more information about this behavior, please check out the Intel website below. http://www.intel.com/support/processors/sb/CS-031174.htm
Besides, if you have only one pc of memory module, please install it into the DIMM slot of DDR3_2 or DDR3_4 as our menu mentioned on page 12 below. Otherwise, the system won't boot when you insert the RAM into DDR3_1 or DDR3_3.
Can I install an external PCI Express graphics card and use it in parallel with Intel graphics?
According to the datasheet of Intel 5 series chipset, Intel graphics cannot be used along with an external PCI Express graphics controller. Installing a PCI Express graphics controller will disable Intel graphics. Please refer to the following website for more information about Multiple Display.