Intel Arc graphics cards stand out for various features, and one of them is a heavy dependence on Resizable BAR technology. So big that Intel itself directly advises owners of older platforms without support for this technology to stick with other video card manufacturers. That is, buy Nvidia and AMD adapters.
Recall that the Resizable BAR technology (AMD calls it SAM) allows the processor to access the entire GPU frame buffer at once, and not in blocks of 256 MB, as in the absence of such technology. And Intel video cards, due to certain features of their architecture, are highly dependent on this technology. Various tests have already shown that without the activation of Resizable BAR, the performance of Arc adapters is significantly reduced, and sometimes drops catastrophically.
At the same time, older platforms do not support the technology, so Intel directly admits that in such cases it is better to choose competitor’s video cards.