[terrybear]

Just to confirm/dig around on the ram modual thing.

Test Rigs in reviews:

HWC
Asus Sabertooth 990fx
2 x 4 GB G.Skill TridentX DDR3-2400

Anandtech
ASUS Crosshair V Formula
4 x 4 GB G.Skill Ripjaws X DDR3-1600 9-9-9-20

Xbit labs
ASUS Crosshair V Formula
2 x 4 GB, DDR3-1866 SDRAM, 9-11-9-27 (Kingston KHX1866C9D3K2/8GX)

Hardoxx (since its sencored i believe still)
ASUS Crosshair V Formula
2 x 4 GB Corsair Vengance DDR3-1333

Toms hardware*
ASRock Fatal1ty 990FX Professional
16 GB (4 x 4 GB) G.Skill DDR3-1600, F3-12800CL9Q2-32GBZL @ DDR3-1600 at 1.5 V

*"The FX-8350 officially supports modules running at up to 1866 MT/s, so this could be a potential performance issue if the platform is bottlenecked by bandwidth. Fortunately, it's not. We ran spot-checks on several benchmarks in order to make sure our decision to use 16 GB of DDR3-1600 instead of DDR3-1866 wouldn't reflect poorly on Vishera."
Sandra 2013 Beta results showed only 1 gb/s in bandwidth less between 1600 & 1866

To me this gives kinda mixed results ... so 4 x 4 gig DDR3 1600 & 2 x 4 gig DDR3 1866 are fine? But what of 4 x 4 gig DDR3 1866 ? 2 or 4 x 8 gig of DDR3 x ?