However, that usually does not make any practical difference when comparing a fairly recent i7 to the Apple Silicon CPUs. There are minor advantages to modern CPUs in terms of having a performance surplus that allows you to enable better memory compression than you would on a really old system - and there are some benefits of having multiple page sizes, etc. As the i7 CPUs and the Apple Silicon CPUs are all 64-bit processors, there's not much about the CPU that determines "RAM-efficiency" - that is almost entirely down to the operating system and your applications. The question of "RAM-efficiency" really hasn't got much to do with the CPU itself. Knowing exactly the specific models you're comparing is vital here. There's more than a factor of 10 difference in performance between the slowest i7 processors and the fastest i7 processors. It is impossible to say with the information you have given. Some iPhone and iPad apps can run on your M1 Mac, great for developers to port apps to desktop.Universal Control with newer Macs and iPads is very cool.M1 can't easily use Intel based virtual machines, like VirtualBox, etc.Thunderbolt cables are not cheap, but very fast, I was running Migration Assistant at 1800 MB/Sec, that's crazy (I only had TB3 cable between 2 M1 macs, wish I had TB4 cable). SSD and other IO speed is much better than older Macbooks.Use this site too,, they have listed many M1 ready apps. Running Intel apps will slow it down a lot and eats up a lot of resources. Make sure you check the Activity Monitor, look for all Intel apps that are running, go and hunt down the M1 ready version.
To share a couple more things from my recent upgrade: And with better resell value at the end.) :)
(Consider spending the extra 200 bucks to get to 16GB RAM and your new upgrade will be every bit/byte better, it will help your new mac to last for another 5-7 years. T2 features embedded are often overlooked too, it is much faster for some "niche" sec to encode/decode videos/images or just for better FaceTime quality with it. SSD read/write is much faster than the 2015 system. The overall system is much faster with latest architecture. If you handle lots of large videos or photos, you probably would be struggling on the 16GB intel a bit anyway, talking about opening many files of hundreds of MB or a few GB loaded in RAM like photos/videos/Database/etc. Your concern about RAM usage efficiency, it depends on your use case. (Geekbench on CPU is clear, I have attached the results below too.) It is subjective and I am sticking my neck out there, yes, M1 based MacBook Air or Pro, even at the lowest spec of 8GB RAM can easily outperform the top of class 2015 MacBook. Tested quite a few old macbooks and even old top spec trashcan MacPro. Just upgraded my intel based systems to M1 too, so did quite a lot of benchmarking over the weekend.