I've just purchased a DH87MC motherboard and I have the following issues:
1. When I enable XMP, in BIOS I can see the ratio going to 12 and result going to 1600MHz but the final result in windows is 1333MHz. Only when I manually select 1600 then it works fine.
2. Usable memory is 7.8GB, even though I've disabled onboard graphics.[Windows7 x64 Professional]
3. The system memory buss is at 99.77 instead of 100MHz, resulting in lower frequencies for my CPU [i7 4770]
I have the latest BIOS installed 
Any suggestion is kindly appreciated.
As it has been indicated by Peter Wertz and Dr. Strangelove at:
The amount of memory that you see reported would be expected.
I have to acknowledge that we may need to test on that XMP issue you are reporting, so please, provide the following information to move further on this:
* Board Altered Assembly Number (AA# ):
* Board Serial Number (SN# ):
* BIOS version:
* Processor model:
* Memory part number and manufacturer:
* Power Supply model and wattage:
* PCI Express* card manufacturer and model:
Please use the Intel® System Identification Utility using the following site:
That will generate an 8 digits code called Report Reference ID. Please let us have that code, this will provide us information on what is being detected on your system.
Rerefence number 0199 5663
AA - AAG74242-401
SN - BTMC317004VZ
BIOS - 0047
PSU - Antec Earthwatts 500W
GPU: Gigabyte GeForce GTX 260 216P GV-N26OC-896I
I cannot set different voltage for RAM, it seems to get stuck at 1.5V instead of 1.65 which I needed for the HyperX pair
Thank you for the feedback. In fact this might be related to using the memory at a voltage that is not the tested one by the memory manufacturer.
Thank you for your patient. I just received information from engineering that this issue has been fixed with new BIOS update.
Please access the link below to get latest version 0153: