I upgraded from Debian Bookworm (Stable), which has kernel 6.1, to Debian Trixie (Testing), which has kernel 6.4. Until then, I couldn’t overclock my GPU’s VRAM beyond 1750 MHz. With kernel 6.4, I can overclock it as far as AMD will allow - 1860 MHz. If my 5600 XT hadn’t been locked down by AMD, I’d be able to go further than 1820 MHZ on the GPU and 1860 on the VRAM.
That’s interesting; kernel 6.4 enabled VRAM overclocking on my 5600 XT while disabling it on the 6900 XT.