ARM are more efficient and can still reach a faster speed (assuming you mean x80_86 or x86_64). And the value of open source and lack of monitoring unit makes them better than intel/amd.
I was strictly talking about price/performance, i doubt few combined Raspberry Pi could be faster than desktop.
Do you think it can emulate ps3 and ps4 for the future development of retropie?
Doubtfully, even high-end PC struggle to run PS3 emulator, except we're talking about
distant future.
https://en.m.wikipedia.org/wiki/PlayStation_3_technical_specificationsIt's processors combined are apparently 240 gigaflops which is about a quarter of a speed of an nvidia titan 16gb (from a few years ago).
Computer emulators struggle because computers work differently and have a base operating system and the emulator on top and have to keep translating. An emulator alone might make it faster...
A lot of companies are considering ditching 8664 in favour of other things as far as I can tell.
Microsoft seem to be trying to dump as much as possible onto graphics chips and apple were considering using arm chips instead of 8664.