1066 and 1333 are too slow.

DDR3 1600  must be used.

Low Density 1.35v

4 gig dimms max size.

1R or 2R not 4R.

DDR3 1066 = (PC3 8500)  too slow

DDR3 1333 (PC3 10600)  too slow

DDR3 1600 (PC3 12800)  This is the REQUIRED Speed for loading 16 Gigs of ram and it must be LOW Density.

DDR3 PC3-12800 • 9-9-9-24 • Unbuffered • NON-ECC • DDR3-1600 • 1.35V •  512 Meg x 64 •

Many INTEL Chipsets cannot use 4 rank or 8 rank memory.

They must be low density 1R /2R or they don't work period end.

The term “rank” was created and defined by JEDEC, the memory industry standards group. On a DDR, DDR2, or DDR3 memory module, each rank has a 64-bit wide data bus.  In its simplest form, a DIMM with DRAM chips on just one side would contain a single 64-bit chunk of
 data and would be called a single- rank (1R) module.  DIMMs with chips on both sides often contain at  least two 64-bit chunks of data and are referred to as dual-rank (2R) modules.  Some DIMMs can have DRAM chips on both sides but are configured so that they contain two 64-bit data chunks on each side—four in total—and are referred to as quad-rank (4R) modules.

Following up on this:

I tried to install four 4-GB DDR3L-1600 UDIMM modules, and the machine left the 3 and 4 LED lights up, indicating an error message. SpeedStep, if you're still around, why can I not use these?