No more so than any SoC these days. What do you mean? They have extensions sure, but so does x86.
But they're not extensions, a lot of is actual sub processors within the SoC.
For example, a lot of ARM SoCs now have something like a Cortex-M0 as their PMC, they have another custom DSP that handles audio, they multiple DSPs that handle video encoding, decoding, transcoding, etc. simply because the ARM cores are not powerful enough and not general purpose enough to do a good job doing these things. Ok, so some of these things are needed to make an SoC work, but ARM based SoCs have many more sub processors than x86/x64 CPUs have.
Look at the Renoir die shots that were posted last week as an example, not taking the GPU or interface parts into account, how many sub-processors are there in these? AMD has their Platform Security Processor, but that's it afaik. As this is an APU, it obviously has a media engine as well, which most likely contains some kind of DSP at the very least.
Apple is relying on a lot more additional sub-processors to get tings done, as per below. They have an always-on processor, they have the crypto accelerator, a neural engine, a machine learning accelerator (aren't the last two the same thing, more or less?) and a camera processor. Ok, so the last one is because this is more of a tablet chip design, but my point here is that x86/x64 doesn't rely on as many extra bits, instead the rely on raw power, for better or worse. Video codecs is one of the simplest examples, as I pointed out in my previous post in this thread. Every time there's a new video codec, a new hardware block has to be added to ARM SoCs for them to be able to play back the codec, unless it's a very simple codec, since the CPU cores are often not capable of playing back video files based on new, more efficient codecs. Yes, this has been an issue in the past with x86/x64 systems too, both H.264 and H.265 had problems on older CPUs and would need 90-100% of the CPU to do software playback. However, on an ARM based SoC from the same period, the same files, simply wouldn't work, due to reliance on fixed function video decoders.
I'm not saying that x86/x64 platforms aren't using more and more of these sub-processors, but most of them seem to be closely tied in to the GPU, rather than the CPU. It's obviously hard to do an apples to apples comparison (no pun intended), as the platforms are so different architecturally. My point was simply that Apple is going to have to be on the cutting edge with these sub-processors all the time and if they bet on the wrong standard, then you won't be able to watch some content on your shiny new Mac, as the codec isn't support and might never be.
It's nigh on impossible to predict what will be the winning standards and as much as most companies bet on H.265, it seems now that, at least to some extent, that VP9 and AV1 are gaining popularity due to being royalty free. That means a lot of older ARM based SoCs will be unable to play back this content, due to lack of a decoder, whereas both can be played back on a regular PC just fine.
Sorry about coming back to the video codec thing all the time, but it really is the simplest example which will continue to cause the biggest problems in the future, as long as we don't have a single standard that everyone agrees to use.
Regardless, ARM processors to date, are a lot more limited in terms of what they can do on their own, without support from these additional sub and co-processors.
