Okay, now that I have publicly egged my face
with my last post about the 2x8GB ram experiment on my 790i Ultra SLI, here's another way I found to get 16GB of RAM that does seem to work, so far. At least, it survived 4 hours of Memtest without error. I haven't had the time to do any more stressful testing yet.
The objective, as before, was to get 16GB of RAM working on my system.
The system: 790i Ultra SLI motherboard. QX9770 CPU, clocked to 3.6 GHZ. FSB is 1600. One video card, a new GTX660Ti with 2GB. Windows 7 Ultimate x64 SP1. One SSD, two standard HD.
The RAM: Patriot 4x4GB DDR3-1866 (PC3-15000) Division 4 Viper Xtreme kit. Model #PXQ316G1866ELQK. This memory, like most new stuff, is rated at 1.5V. Cost about $100.
Memory settings: All the timing was simply left Auto (Optimal). Turns out the Auto setting for this RAM actually comes up as DDR3-1600, 9-9-9-24, which was fine with me.
Voltages: left at default except for RAM voltage of 1.6V, SPP at 1.40V, and MCP at 1.55V.
I did not turn on Link or Sync although I probably could have. P1 and P2 both left on Auto.
Testing: So far all I have had time to do is use Memtest86+ v.4.2. First I inserted one stick (in slot 3). Booted into Memtest, which I let run for one full pass. No errors, so I shut it down and put in a second stick in slot 1. Memtest again; again one full pass with no errors. (Interleave worked too, the measured memory speed increased by about 35%.) Getting brave, I inserted the other two sticks. Booted into Memtest again. (The memory speed was the same as with two sticks.) This time I let it run for two full passes, over 4 hours' worth. No errors!
Windows 7 and Windows 8 both boot up just fine, run perfectly, and show 16.0GB.
If anyone has any further suggestions for testing, or comments, please reply to this thread. I'll try Linpack or some other stress test or game when I have the time. But for now, I plan to enjoy my "new" system.
Keith