There are no guarantees even if everything operates on the same core. Rust docs have some details: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._mm_sfe...
Intel's docs are unfortunately spartan, but the guarantees around program order is a hint that this is what it does.
Similarly, if I look up MOVNTDQ in the Intel manuals (https://www.intel.com/content/dam/www/public/us/en/documents...), they say:
“Because the WC protocol uses a weakly-ordered memory consistency model, a fencing operation implemented with the SFENCE or MFENCE instruction should be used in conjunction with VMOVNTDQ instructions if multiple processors might use different memory types to read/write the destination memory locations”
Note _if multiple processors_.