Ryzen

Ryzen is Zen microarchitecture.]] Its goal is to directly compete with Intel's Broadwell-E processor line, primarily the Core i7-6900K.

Firmware
Microcode/firmware updates to be determined...

Kernel
Enable support for Ryzen hardware in kernel 4.11.0:

Those using with the   USE flag will have additional Processor family options made available:

This enables  to be set for the kernel's  process.

GCC 6.3+
GCC 6.3+ has support for the  compiler optimization. For optimal performance, this can be enabled in.

GCC 6.3 is not presently optimized for Ryzen.

GCC 5.4
While GCC 5.4 does not support zen core specific optimization,  has been shown to be functional and stable. However, since Zen dropped the instruction set extensions FMA4, TBM, XOP and LWP, they should be disabled accordingly:

Optional, but may produce better code: Add new instruction set extensions introduced with Zen individually (ADCX, RDSEED, MWAITX, SHA, CLZERO, XSAVEC, XSAVES, CLFLUSHOPT, POPCNT), using  (Bulldozer Version 4 i.e. Excavator) as the starting point:

Segmentation faults during compilation
If segfaults are encountered during compilation process on Zen it might be anything from software bug to a hardware bug. There have been reports of success and failure. The recommendation is to disable all overclocking and set proper timings for RAM. These problems are likely to be fixed in the future by AMD microcode update and/or GCC update.

Please ensure the most recently compiled binutils is selected via eselect binutils list [1] x86_64-pc-linux-gnu-2.27 [2] x86_64-pc-linux-gnu-2.28 *

an older instance of binutils could be built against older opcode facilitating crashes due to poor linkage

Please ensure RAM voltage and timing are correct for your RAM, BIOS's are conservative while performing autosetting consider downgrading BIOS to the most stable. ASUS and ASRock have been known to push very beta bios's that have shown to be very unstable

Related forum topics: 1 and 2. And a Phoronix forum topic.

Ryzen users can also fill Gentoo & Ryzen config & stability questionair to help out collecting data. See also the datasheet generated from above questionair.

External resources

 * http://www.phoronix.com/scan.php?page=article&item=amd-ryzen-znver1&num=1 - Phoronix compiler optimization benchmarks for Ryzen 7.