Data Latency is the time taken to transfer data to a processor (a core in a CPU or GPU).
| Data Location | Average Latency | Normalised Human Time |
|---|---|---|
| 3 GHz CPU Clock Cycle | 0.3. ns | 1 s |
| CPU Cache | 0.9-28 ns | 2 s - 1 min |
| RAM | 70-100 ns | 3.5-5.5 min |
| Solid State Disk (NVME) | 7-150 µs | 2 hrs to 2 days |
| Hard Disk Drive | 1-10 µs | 11 days to 4 months |
| Another Supercomputing Node | 100-1000 ms | 3-30 years |
Depending on the type of work you are doing, the amount of data you are working and the type of system you are working on, your work will be:
I/O Bound: Progress depends on the speed of input/output operations (e.g. transferring data between the RAM and a disk drive).
Memory Bound: Compute time depends on the amount of Memory (RAM or VRAM) available to hold working data.
Procesor Bound: Progress is limited by the speed of processors in the CPU or GPU.