Intel Boosts Gen7 GPU Vulkan Compute Performance By ~330% For Geekbench

Intel's open-source "ANV" Vulkan driver for Linux doesn't see much attention for pre-Broadwell hardware but today it saw a big improvement for Vulkan compute on aging Gen7 Ivybridge/Haswell era hardware.

Jason Ekstrand, the lead developer of the Intel ANV Vulkan driver, discovered that in their driver's pipeline code the data cache functionality would end up being disabled when a shader was pulled out of the pipeline cache. For Broadwell/Gen8+ the data cache bit was being ignored but this oversight ended up having huge implications for Gen7 Intel graphics hardware (Ivybridge/Haswell) as the oldest supported by Intel's Vulkan driver.

When fixing up the Intel ANV driver to always use the data cache, the Intel Gen7 performance for Vulkan compute workloads has improved massively. Ekstrand found that the Geekbench 5 performance for the Vulkan compute test improved by 330% on Haswell GT3 hardware. Yes, 330%.

That's great news if you are comparing Geekbench scores with old Intel hardware, but keep in mind this is only for the Intel ANV Vulkan driver (not OpenGL) and Vulkan compute workloads in particular stand to benefit the most. As well, there isn't too much in the way of Vulkan software that runs nicely on aging Ivybridge / Haswell era, thus Geekbench stands out as one of the few relevant cases.

Always enabling the data cache for the Intel Vulkan Linux driver is present in Mesa 20.1 development code and is flagged for back-porting to the Mesa 20.0/19.3 stable series.