The advantage of four DIMMs extends beyond the ability to support quad-channel platforms. Lower-density DRAM ICs still have a noticeable per-gigabyte price advantage over higher density parts. They also tend to overclock more easily, to the point that we can't even find a 2x 16GB (32GB) kit in-stock at the same DDR4-3200 data rate as today's 4x 8GB (32GB) test kit. And even buyers who find themselves stuck with only a dual-channel motherboard can appreciate the slight performance increase we're seeing on our Z170 test boards when all four slots are filled.
And speaking of Z170, the Skylake processor's advanced memory controller makes overclocking so much easier than its Haswell-E predecessor that I have switched to it by default, reverting to X99 only when requested by the manufacturer. Manufacturers also like to see their products reach higher data rates in a review, and we have yet to receive such a request.
That brings us to the F4-3200C16Q-32GTZ kit from G.Skill. Its part number reveals that this is a DDR4-3200 CAS 16 Quad-Channel, 32GB, Trident Z model. It will also work on a Dual-Channel motherboard, but I'm leaning on Skylake to push this RAM well past its DDR4-3200 rating.
XMP allows the RAM to be configured semi-automatically to its custom 1.35V voltage level in addition to its 3200 MHz data rate and 16-16-16-36 timings. The actual setting for XMP is in the firmware of most consumer motherboards, though a few have a handy onboard switch to instruct firmware to enable these settings without actually entering its GUI.
DDR4 Rated Specification Comparison
We haven't tested many 4x 8GB kits yet, and Adata's XPG Z1 DDR4-2400 is the fastest we have to compare. We do have a bunch of 4x 4GB kits though, including the G.Skill DDR4-3600 kit I use for motherboard overclocking evaluations and the DDR4-3200 kit recently tested for Corsair.
The overclocking chart points out the reason for selecting Skylake, and particularly the Z170X-Gaming G1 motherboard, in an effort to find each memory kit's maximum data rate. The previously-stubborn Corsair Vengeance LPX 16GB DDR4-3200 leaps to DDR4-3636, and the Trident-Z DDR4-3200 kit's nearly-matched capability becomes even more impressive when we consider that it's twice the capacity at 32GB.