perf: hipo2npz memory efficiency
#3602
| Job | Run time |
|---|---|
| 4m 51s | |
| 4m 15s | |
| 4s | |
| 2s | |
| 3m 1s | |
| 2m 58s | |
| 1m 9s | |
| 1m 41s | |
| 6m 15s | |
| 2m 49s | |
| 3m 13s | |
| 3m 50s | |
| 1m 48s | |
| 4m 28s | |
| 1m 51s | |
| 3m 16s | |
| 2m 43s | |
| 3m 5s | |
| 0s | |
| -1s | |
| 3m 32s | |
| 38s | |
| 3s | |
| 55m 31s |