We’re still talking about a supercomputer… It has a storage cluster attached, which is way faster than a single HDD or even SSD. In my benchmark with 8 GB of data I reached way over 12 GB/s (using two nodes).
The support of the super computer said, the storage is so fast, it shouldn’t be the bottleneck. But the network actually could be the bottleneck, which is 100 GBit/s per Node.