If you have a very old motherboard, then the likelihood is you would have an old CPU also. This vulnerability is as far as I can tell is meant to be for the modern range of CPUs. That said I haven't found a source that specifically reports what CPUs are affected.
I did have a link but can't yet find it. I have a Core i5 which was definitely on the list (as were the others in the range, of course). Since it was a small company that made the PC I have to find the patches manually, but yes, it seems at the moment the MSI website only lists some gaming 100, 200 and 300 series for BIOS patches; mine hasn't been touched for nearly three years.
My wife has an HP Pavilion but her particular one doesn't seem to be listed on HP's support site, just other (presumably newer) versions. She has an AMD processor so perhaps it's less important. Still, it's frustrating not being able to update either of those nor having the Win 7 update listed (I'd rather wait for that if possible. If it doesn't show for us on Tuesday I guess I'll manually do it, but neither of us are tech-savvy); I just feel sort of afloat.