On page 14 of the DX48BT2 manual Intel states the following:
For 1600 MHz memory, only two DIMMs are supported for a maximum of 4 GB utilizing 1 Gb memory technology. DIMMs should be configured as a matched pair equal in speed and size in DIMM 0 and DIMM 1 of channel B.
On page 18 of the X48 chipset datasheet Intel states the following:
When using DDR3-1600 XMP DIMMs the X48 MCH supports single DIMM per channel where DIMM1 is populated and DIMM0 is not populated.
On the support page of the DX48BT2 Intel states the following:
If you are using DDR3 1600 MHz DIMMs, you should only populate two of the four DIMM slots and specifically one slot in each channel. Use slot 1 of each channel (black connectors).
So it appears that the chipset datasheet is right and the furthest DIMM slot of each channel (black) should be populated. However memory technology evolved since then because I can successfully run my DX48BT2 with 8GB DDR3-1600 8-8-8-24 (2x4GB) in the blue DIMM slots or in the black ones and with 16GB DDR3-1600 8-8-8-24 (4x4GB) using Crucial Ballistix Elite BLE46301608DE1TX0. The trick is to boost the FSB voltage to 1.325V and the MCH core voltage to 1.375V otherwise the system won't be stable. However with 16GB the system becomes significantly slower even if all the memory tests pass without any error. No matter which BIOS version I use up to the latest (2006) I can't resolve this problem.
The answer given by Crutiatus is correct; the motherboard will handle two memory sticks at 1600 MHz when using the two black slots.
See Intel® Desktop Board DX48BT2 - System Memory at: http://www.intel.com/support/motherboards/desktop/dx48bt2/sb/CS-028495.htm
See page 16 in the following document: http://www.intel.com/assets/pdf/prodspec/dx48bt2-tps.pdf
Please bear in mind that these motherboards were made in 2008 based on technologies and manufacturing standards of the time. If you are using memory recently made it is expected to face compatibility problems.
Nowadays memory sticks are built based on newer architectures and higher SDRAM density which won’t be properly handled by the Memory Controller Hub (MCH) of these boards. We recommend you following the specifications of the web document CS-028495 quoted above.
What Crutiatus did with his board using 4GB and 8GB memory sticks is not a supported practice and we don’t recommend changing voltage values for any component.
If your system is not stable and is randomly freezing up we suggest you doing deeper hardware troubleshooting. Here some general recommendations:
- Make sure the memory is fully supported by the motherboard
- Test memory running at lower speed (1333Mhz) and compare results
- Test the system using only one memory stick in the four different slots (one at a time). This is to identify a possible bad slot.
- Re-install the operating system from scratch or use a spare Hard Disk Drive and install a fresh copy of Windows
- Test a different power supply.
- If possible, test a different and compatible CPU.
- Mare sure all of the motherboard drivers and BIOS are updated.
With this link you can find all of the motherboard drivers, just pick drivers from the “download type” and select the correct operating system: https://downloadcenter.intel.com/product/33394/Intel-Desktop-Board-DX48BT2
The latest BIOS can be found this other link: https://downloadcenter.intel.com/download/18302/BIOS-Update-BTX3810J-86A-
If the problem persists then you could be facing a hardware failure with the motherboard or the CPU.