I think there are a few things to look at regurding this, Intel has been
recomended for a lot of people because graphics (at least the built in
ones) are a non-issue (except the Atom ones which otherwise are quite nice
Audio CPUs).
The second thing is that people have been tweaking Intel machines for a
long time. So the tweaks are well known. AMD has had a history of using
tricks and hacks to at least look like they are out performing an Intel
equivelent. Different speeds from core to core etc. And while none of
these things should be a problem so long as they are easy to control,
maybe not that many people know how. People have just used what is known
and easy to use. Intel has tended to contribute to the linux kernel to
make sure everything works. I am not so sure about AMD.
So I don't think the AMD CPUs are bad, there is just less info on
tweaking. Another thing to remember is that modern Intel mother boards are
not as easy to get good performance on either. All the "affordable" Audio
units are now USB which was never really designed to be low latency in the
first place. So low latency has gone from being able to get solid sub ms
latency to good 5ms latency so far as I can tell (one way jack latency
only). Either the world has found out that 5ms is "good enough" or those
who want more will have to spend more.
What is being said a lot on the web is, that AMD CPUs have a slower memory controller.
I don't really know how to check that but that should be relevant for low latency work.
On the other hand, it could be Intel spreading misinformation, I mean they have done that before.
In the gaming world it seems that indeed AMD processors are about 10% slower when compared against same spec Intel machines.
There the single core performance is said to be the most important factor.
I don't know if that is true also for the audio world.
Another thing that has changed is how USB is implemented. On a lot of
mother boards it is impossible to get one's mouse and keyboard on a
different USB bus from the audio interface. It seems to only sure way is
to add a PCIe USB card for the audio box. It used to be that one side of
the computer was one bus and the other side was another... not any more.
The computer does internal routing to put all of them on one bus except
may be USB3 stuff (which I have none of).
That is true especially for laptops, as I had to find out.
Until now I have worked on a Lenovo laptop from 2014, and the all USB sits on only one bus.
Best regards
Moshe