However, since all the code is open source, third parties often do benchmarks across platforms. Michael Larabel from Phoronix does a really good job of this.
I mean, it makes perfect sense to me that Intel would only care about optimizing (or even supporting) their software on Intel chips, but I'm sort of surprised that you don't have AMD systems to test on just to compare performance.
Wouldn't it be something that you (or management, or whoever) would want to know if you were about to release a version that had much worse performance on AMD systems because of a regression ("Intel is intentionally crippling AMD CPUs!") or much better performance ("Intel released a new update but it runs better on AMD at half the price lol")?
If it's a small team then you may not have the budget (or want to spend it on that), but surely it would be nice to know either way?
I guess I just get suspicious whenever I see MKL mentioned.