For VMware workstation it is very noticeable and there are workarounds. How much random software is being scheduled on the wrong cores and not noticed because it's "fast enough" or people don't have a baseline of performance to expect?
After i got a work laptop with e cores i will make sure to avoid them for any personal devices i buy myself.
IMHO too many engineers (software devs in particular) think things are fine if there is a way to configure things the way you want. IMHO having to worry about which cores a process is running on is unacceptable. I'm kind of dreading AMD following along with perf and efficient cores.
The asymmetrical architecture in the 7950x3D unfortunately results in similar (but less extreme) issues to e-cores. Only one CCD has a big cache, while the other clocks higher. So, it can happen that processes which love the extra cache end up running inefficiently on the higher-clocked smaller-cache cores, or the other way around, where clock-sensitive processes are throttled by running on the 3d cache cores.
