4 ms·
HPC is usually a balancing act between the performance you gain by adding another node and the time you lose passing messages around. You can't just keep adding
by Sean1708 10y ago
HPC is usually a balancing act between the performance you gain by adding another node and the time you lose passing messages around. You can't just keep adding nodes without introducing some form of shared memory because you will very quickly become limited by your bandwidth.
- jabl 10y agoWhat is shared memory, if not message passing (with some particular semantics) implemented at the hardware level? I.e. messages == cache lines, semantics == cache coherency protocol. Particularly so when you go to (nowadays) multi-socket systems, where everything is NUMA. There is a smallish sub-segment of the HPC market where customers really want large CC-NUMA systems, AFAIK SGI (whoever owns them these days, HPE?) is more or less the only supplier. But the vast majority of HPC is clusters using message passing. If I were to choose some awfully general statement about HPC, rather than yours I'd choose "supercomputers are not tools for solving small problems faster, but rather tools that make solving larger problems possible". I.e. the entire weak vs. strong scaling thing etc.
- Sean1708 10y agoTo be honest, yours is probably the far better statement.