Google security blog says it is.
> These vulnerabilities affect many CPUs, including those from AMD, ARM, and Intel, as well as the devices and operating systems running them.
https://security.googleblog.com/2018/01/todays-cpu-vulnerabi...
> These vulnerabilities affect many CPUs, including those from AMD, ARM, and Intel, as well as the devices and operating systems running them.
https://security.googleblog.com/2018/01/todays-cpu-vulnerabi...
Treating them as a group, ignores the very real differences in effect.
https://googleprojectzero.blogspot.com/2018/01/reading-privi...
>6.4 Limitations on ARM and AMD We also tried to reproduce the Meltdown bug on several ARM and AMD CPUs. However, we did not manage to successfully leak kernel memory with the attack described in Section 5, neither on ARM nor on AMD. The reasons for this can be manifold. First of all, our implementation might simply be too slow and a more optimized version might succeed. For instance, a more shallow out-of-order execution pipeline could tip the race condition towards against the data leakage. Similarly, if the processor lacks certain features, e.g., no re-order buffer, our current implementation might not be able to leak data. However, for both ARM and AMD, the toy example as described in Section 3 works reliably, indicating that out-of-order execution generally occurs and instructions past illegal memory accesses are also performed.
Seems like the possibility exists that AMD/ARM could be affected, based on the behavior they saw, but they were not able to successfully verify.
but it might also be reasonable in a different architecture to fetch 0 straight away to the micro op when the memory access is invalid and set a flag to raise the exception as well. in this situation you don't have the problem because you are just shuffling around invalid data.