Intel Arc A7 GPUs Become Useless Without Customizable BAR

TechPowerUP has tested the Intel A7 GPUs with systems that are not officially supported. This points to the absence of ResizableBAR support and an outdated PCIe Gen3 system. Intel officials have emphasized the need for ReBAR support for the effective operation of Intel GPUs. However, this does not preclude the use of Arc GPUs without this technology.

The results may be a little different, but without ReBAR, Arc’s overall performance can drop by up to a quarter. According to TPU testing, the absence of PCIe Gen4 support is less important than the lack of ReBAR. The older PCIe Gen3 standard has only a 0-2% difference in all tests. In contrast, the absence of ReBAR can reduce performance by 76-80%, which is a significant difference.

You really need resizable-BAR for the Arc A770 to perform as advertised. The card is simply unusable without it, and Intel said that during the marketing events leading up to this launch. With Resizable-BAR turned off, performance drops like a rock to just 77% of the performance you’d get with it turned on at 1080p, and just 76% at 1440p—almost a quarter of the performance lost. But that is the average of all game tests and gives an incomplete picture.”

This means that systems without Gen4 support but with ReBAR support can still use Arc GPUs with no significant performance degradation. This includes the Intel 10th Gen Core or Ryzen 5000G series, which is limited to the Gen3 standard, and several systems that have received unofficial ReBAR support, such as Intel Coffee Lake.

Via TechPowerUP

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