I am running sometimes with 8GB modules (Hynix HMT31GR7BFR4C-H9). At the moment board with one X5690. Managed to post with very weird settings. No post with setting mem in bios 800/1066 only 1333 and needed to rise IOH to 1,425V. Booted @133 with one module and fixed mem timings. Then 3 modules bclck up and 6 modules. Important to set manual as much in bios concerning mem settings/timings as possible. When settings and timings right not much difference 3 or 6 modules. Sometimes after cold boot or after BSOD unable to post, need to start from beginning. Got board running stable for 2 weeks. Now again no matter I try need to run @175, was able to run tests these 2 weeks @181/182. I am bit afraid about memory, but not have found way to run it at lower speed 800/1066. Just not able to post. Hope new bios solve memory bug and can my 48 GB within specifications