TechPowerUP conducted tests on the Intel A7 GPUs using systems that are not officially supported. This indicates the absence of ResizableBAR support and an outdated PCIe Gen3 system. Intel officials have stressed the need for ReBAR support for the effective operation of Intel GPUs. However, this does not exclude the usage of Arc GPUs without this technology.
The results may be a little different, but Without ReBAR, Arc’s total performance may decrease by up to a quarter. According to TPU testing, the absence of support for PCIe Gen4 is less significant than the lack of ReBAR. The older PCIe Gen3 standard has just a 0-2% difference across all testing. In contrast, the absence of ReBAR may reduce performance by 76-80%, which is a substantial difference.
“You really need resizable-BAR for the Arc A770 to perform as advertised. The card is simply unusable without it, and Intel said as much throughout the marketing events leading up to this launch. With Resizable-BAR disabled, performance drops like a rock down to just 77% of the performance you get with it enabled at 1080p, and just 76% at 1440p—nearly a quarter of the performance lost. But that’s averaged across all game tests, and presents an incomplete picture.”
This implies that systems without Gen4 support but with ReBAR support may still employ Arc GPUs without significant performance degradation. This includes the Intel 10th Generation Core or Ryzen 5000G series, which are limited to Gen3 standard, and several systems that obtained unofficial ReBAR support, such as Intel Coffee Lake.