So how's it play?
High-level architectural discussions are one thing, but everybody wants to know what Vega silicon will look like in shipping products. AMD constantly demurred about actual implementation details of its Vega chips last month, but we've speculated that the Vega-powered Radeon Instinct MI25 would pack 4096 stream processors running at around 1500 MHz thanks to its 25 TFLOPS of FP16 power.
AMD did have an early piece of Vega silicon running in its demo room for the press to play with. In the Argent D'Nur level of Doom's arcade mode, that chip was producing anywhere between 60 and 70 FPS at 4K on Ultra settings. Surprisingly, the demo attendant let me turn on Doom's revealing "nightmare" performance metrics, and I saw a maximum frame time of about 24.8 ms after large explosions. I also noted that the chip had 8GB of memory on board, though of course we couldn't say what type of memory was being used.
Though that performance might not sound so impressive, it's worth noting that all of the demo system's vents (including the graphics card's exhaust) were taped up, and it's quite likely the chip was sweating to death in its own waste heat. By my rough estimate, that puts the early Vega card inside somewhere between the performance of a GTX 1070 and a GTX 1080 in Doom. If that's an indication of where consumer Vega hardware will end up, we could have a competitive year to look forward to from AMD. Until we learn more about Vega, though, we're left with only this tantalizing taste ahead of the card's first-half-of-2017 release.