Mesa RadeonSI Lands Possible Vega/Raven Performance Improvement

Earlier this month AMD's Marek Olšák posted RadeonSI patches for a scissor workaround affecting GFX9/Vega GPUs including Raven Ridge, which were based upon a RADV driver workaround already merged that helped affected games by up to ~11%. A revised version of that patch is now in Mesa 18.2 Git.

Marek has merged his latest patches that implement the scissor bug workaround without causing a performance drop. The main patch notes, "This might improve performance on Vega10 and Raven."

Unfortunately, nothing more concrete than that, but I'll be firing up some fresh Mesa Git benchmarks with Radeon RX Vega in the next few days. As we've seen in recent benchmarks though, any help for RadeonSI (or RADV) on Vega is much appreciated as there still is more performance to squeeze out of these latest-generation AMD GPUs on the open-source Linux drivers.

Mesa 18.2 is on track to debut as stable in August.