I don’t understand why the default Fedora install uses /dev/shm/ and not /dev/ram0. Yes, shm is dynamically allocated, but you get very small r/w speeds to RAM via a shm device. Versus nearly full r/w speeds if you use /dev/ram0 (in raw mode, for sure, but even with a filesystem on top of it?)?
Is this even accurate? I haven’t benchmarked it.
Use of shm is an API that apps use.
No idea about what ram0 is useful for.
So no you can of replace one with the other.
Speed will be limited by the spec of your RAM and CPU
not the /dev device.
Can’t you just format /dev/ram0 and use that as a true block device with much less overhead? Yes, you’ll have a set size, but you’ll have more speed?
See man shm_overview to understand what shm is all about.
That is how you would use /dev/ram0. It behaves like a disk and you use it as a disk.
ls -l /dev/ram0
brw-rw----. 1 root disk 1, 0 Feb 13 13:54 /dev/ram0
If it has less overhead than the newer tmpfs file system is unlikely, but without a benchmark we wouldn’t know.