BIOS flashed my reference Vega 56 to a Vega 64 BIOS for identical performance in gaming (as revealed by GamersNexus, the extra shaders on Vega 64 currently make ~0fps difference for gaming when both cards are at the same clocks, which is possible through a BIOS flash for voltage changes on Vega 56).
GPU HBM2 memory was overclocked from 800Mhz to 1100Mhz for 563GB/s memory bandwith (484GB/s on GTX 1080Ti). The GPU core was undervolted to maintain higher actual operating frequencies via less power consumption/thermal throttling.
Overall, it performs slightly better in Firestrike (5%) & total game average fps than a stock FE GTX 1080, consumes 10W less than FE GTX 1080 with the undervolt, was cheaper than a 1070 and is perfect for my FreeSync Ultrawide.
The extra 8 CU's on Vega 64 do not seem to be optimised for gaming at the moment and the hardware is practically the same otherwise. Vega 56 is artificially limited in core and memory frequencies to compete against GTX 1070. This is why an ordinary overclock on Vega 56 achieves +15% performance. The HBM2 memory is limited to 1.25v on the Vega 56 BIOS, still allowing an overclock from 800Mhz to 950Mhz. This alone provides a massive boost to gaming performance as memory bandwith seems to be the main bottleneck on RX Vega. However, flashing the RX Vega 64 BIOS onto Vega 56 supplies 1.35v to the HBM2, allowing the same memory overclock as Vega 64 to 1100MHz. Combined with the core undervolt, this gives +22% performance from stock Vega 56 while reducing power consumption by ~70W (from full power limit setting).
GPU HBM2 Memory Clock (Vega 56 8GB): 800MHz -> 1100MHz@1.35v (950Mhz@1.25v max OC without BIOS Flash)
GPU Core Clock (Vega 56 8GB): 1156-1471MHz -> 1590-1644MHz stable (1610Mhz max OC without BIOS Flash)
GPU Core Voltage (Vega 56 8GB): Variable upto 1150mV max -> 1050mV max (an undervolt reduces power consumption for achieving the same core clock, this reduces heat output by ~5-10°C on Vega (which seems to be overvolted by default), this decreases thermal throttling meaning consistently higher operating frequencies during actual gaming workloads)
CPU Clock (i5 6600k): 3.5-3.9GHz ->4.6GHz stable @ 1.35v for daily use (4.8Ghz@1.45v for benchmarking, 4.7Ghz@1.41v)
RAM Clock (DDR4 16GB): 2400MHz -> 3000MHz CAS15 XMP enabled
Monitor Refresh Rate (LG 29UM68-P): 75Hz -> 80Hz
Monitor FreeSync Range (LG 29UM68-P): 40-75Hz -> 32-80Hz (new 2.5x range automatically enables AMD Low Framerate Compensation)
CPU was overclocked in the UEFI (BIOS). The correct RAM XMP profile was also enabled in UEFI (stock profile for DDR4 is 2400MHz). GPU was overclocked through Radeon WattMan by AMD. GPU BIOS was flashed using ATIFlash by TechPowerup.
Monitor refresh rate and FreeSync range was flashed through CRU (Custom Resolution Utility) by ToastyX.
Here is stock performance on Firestrike (20,095 GPU score): https://www.3dmark.com/fs/13604249
Flashed to Vega 64 + HBM2 overclock + core undervolt (24,282 GPU score): https://www.3dmark.com/fs/13620187
Used for gaming, studying, music production and sometimes video editing & 3D modelling :) Mining ether the rest of the time ;)
Total PC components cost: $1698AUD (~1220USD)
Storage + Monitor + Peripherals: $1257AUD (~900USD)
I was lucky to get a card from the initial batch of Vega 56 at MSRP ($559AUD HIS Vega 56 from PLE Computers, basically $399USD MSRP + 10% GST). PC was built 1 year ago with RX480 before Ryzen on Sep 22, 2016. Vega installed on Sep 12, 2017.