Update 11/05/2022 9:07 am PT
"Intel Arc products do not require the host CSME to update Arc firmware," an Intel spokesperson told Ars Technica. "Firmware updates will work on both AMD and Intel platforms. Arc products have their own Graphics Security Control for firmware updates and leverage existing Intel technology like the HECI interface protocol to implement the firmware update flow."
Upgrading the Graphics System Controller firmware on a graphics card isn't something you'll do very often, but if you own the not-impossible combination of an Intel Arc graphics card and an AMD CPU, you might not be able to do it at all. That's according to the developer (opens in new tab) of a firmware update plugin (opens in new tab) for Linux, as reported by Phoronix (opens in new tab).
The problem revolves around the Intel Management Engine (opens in new tab) (which, for some reason, takes the initialism MEI). This capability has been part of the platform controller hub in practically every Intel chipset since 2008. As a result, MEI is always working while the motherboard receives power, whether or not the PC is switched on (AMD has had an equivalent since 2013, the Platform Security Processor).
The MEI's exact workings are largely undocumented, its code within the firmware obscured, and it uses its own microprocessor (often an Intel Quark). It even has a UNIX-like operating system with access to memory, networking and displays. So this computer within a computer definitely does something, but it's unclear precisely what, and Intel isn't saying.
One thing it can do is update graphics card firmware, and Intel has taken advantage of this capability for its new line of Arc discrete GPU boards. However, this causes a problem for anyone using another vendor's products or systems so old that they don't support MEI.
The issue was discovered as coders attempted to obtain an open-source Linux driver for the Arc boards to work on IBM's POWER architecture. Intel's graphics drivers didn't need to support non-x86 processors before the launch of Arc, and now that they do, the likes of Arm and RISC-V should be able to use the boards. It's not perfect, but work is progressing.
There currently doesn't appear to be a way around the problem without Intel changing how the GSK firmware is delivered. Luckily, these kinds of firmware updates are rare but can add new features, such as last year's update (opens in new tab) that added the resizable BAR functionality to Nvidia's RTX 30-series cards.