[magicalhippo]

But traditional operating systems still assume RAM contents is volatile (because currently it is), most filesystems assume disks are glacially slow etc.

A traditional spinning rust HDD has an effective latency of ~10 ms. The NVME version of the 3DXP has an effective latency of ~50 us, or two orders of magnitude better. Not sure how low the DIMM version will go, but maybe another order of magnitude?

If so, we're talking three orders of magnitude difference. That would radically affect the assumptions going into storage algorithms. Suddenly you can no longer spend millions of instructions trying to avoid I/O. Batching of I/O is also not needed to the same degree. Complex syncing of memory and disk is not needed. Etc etc.

[dragontamer]

> But traditional operating systems still assume RAM contents is volatile (because currently it is)

RAM is only volatile on startup. Certainly not when a VM hibernates and comes back.

[magicalhippo]

> RAM is only volatile on startup.

No it isn't. Anything that needs to survive a power cycle needs to go to non-volatile storage. And this is assumed to be very, very slow.