AMD Explains Image Quality Difference Between Radeon RX 480 And GTX 1080
AMD revealed its Polaris architecture based RX 480 during its conference at Computex 2016. To show the capabilities of their graphics card, AMD did a comparison between dual Radeon RX 480 with CrossFire setup and single GTX 1080.
The results of the demonstration were in favor of Radeon RX 480, however, many attendees noticed that the image quality of the game running on dual Radeon RX 480 setup was different from the game running on GTX 1080.
To address this issue AMD’s Technical Marketing boss, Robert Hallock, took it to the Reddit. He provided the full specs of the system that was being used for the demonstration, which included Core i7-5930K, 32 GB of DDR4 RAM, Windows 10 and for Radeon RX480 the driver was 16.30-160525n-230356E, while for Nvidia 368.19.
Both GPUs were handling some extreme settings of the game at 1080P during the demo with 8X MSAA and v-sync was disabled. Hallock explained:
Ashes uses procedural generation based on a randomized seed at launch. The benchmark does look slightly different every time it is run. But that, many have noted, does not fully explain the quality difference people noticed.
He further went ahead to explain why the image quality was different and that the GTX 1080 does not correctly executes the Ashes of Singularity.
At present the GTX 1080 is incorrectly executing the terrain shaders responsible for populating the environment with the appropriate amount of snow. The GTX 1080 is doing less work to render AOTS than it otherwise would if the shader were being run properly. Snow is somewhat flat and boring in color compared to shiny rocks, which gives the illusion that less is being rendered, but this is an incorrect interpretation of how the terrain shaders are functioning in this title.
He further explained that the snow coverage in Ashes Of Singularity running on Radeon RX 480 was better due to the correct execution of terrain shaders.
The content being rendered by the RX 480–the one with greater snow coverage in the side-by-side (the left in these images )–is the correct execution of the terrain shaders. So, even with fudgy image quality on the GTX 1080 that could improve their performance a few percent, dual RX 480 still came out ahead. As a parting note, I will mention we ran this test 10x prior to going on-stage to confirm the performance delta was accurate. Moving up to 1440p at the same settings maintains the same performance delta within +/-1%.
So do you think that the reason for different image qualities was due to the different executions by both cards? Let us know in the comments.