did you watch the video? GN downclocked vega to furyX frequencies there. so while vega is running 50% higher clockspeeds compared to the downclocked variant, gaming benches are only around 20% higher with the not downclocked vega. that seems pretty strange to me and lets assume some severe bottlenecking is going on.
Just partly, I primary read their article:
http://www.gamersnexus.net/guides/2977-vega-fe-vs-fury-x-at-same-clocks-ipc
Where they don't have Vega @ 1600 Mhz but at stock frequency which is a range roughly around 1300-1500 Mhz, mostly settling down at 1440 Mhz.
PCGH did comparisons with 1050 Mhz for Fiji and Vega and for Vega with 1600 Mhz, where they increased the Power-Target and Fan-Speed to make sure it's staying at that clockspeed.
One part of the synthetics makes it quite clear that Vega is bandwidth starved.
C&P:
- Effective Texture Bandwidth
Now here things are getting really interesting.
That's a bandwidth test where two different types of textures are tested.
One black texture and one with random colors.
Since the recent GPUs are using Delta Color Compression techniques you see a big difference between a black texture where no color deltas are found and the compression can be optimal and a random colored texture where the compression effectively doesn't work.
Nvidia is quite the king here, the difference between the best case and worst case is about105-130% in bandwidth.
GCN Gen 3 only manages 17%, GCN Gen 4 47%.
One possible speculation was that Nvidias Color Compression might not be that much better than from AMD but that the tiled based renderer is helping the color compression technique in addition.
But the DSBR seems currently to be inactive as the trianglebin test doesn't indicate any tiling.
Without the DSBR the results are 52-60% better for GCN Gen 5 with the black texture.
The range is maybe too small to call it a clear improvement over GCN Gen 4, maybe a few percent.
What's more interesting are the results with the random colored texture where the achieved bandwidth is actually 24% lower than from the Fury X, you would expect 6% (484 GB/s vs. 512 GB/s) but not 24%.
The bandwidth utilization is miserbel and explains the limited scaling seen with Vega.
You also see 20% higher memory copy throughput in Aida (336 GB/s vs. 303 GB/s) with the Fury X in comparison to Vega.
