4 ms·

You cannot abstract away a 3 order of magnitude difference in bandwidth and latency.

• pclmulqdq 3y ago
  Where did you get a 3 order of magnitude difference? Are you still using hard drives for your storage medium?
  • osigurdson 3y ago
    Adding two numbers together takes on the order of a nanosecond. Doing the same thing using a rest / http service (like an idiot) in the same datacenter takes on the order of a millisecond. Six orders of magnitude actually.
    • pclmulqdq 3y ago
      I'm pretty sure the parent comment was about storage media, not about network hops and service boundaries. Also, extremely basic REST/HTTP services definitely do not take 1 millisecond even if you are bad at software - the overhead of that stack is in the tens of microseconds if you are doing nothing. For the comparison being referenced here, if you want to compare RAM, the storage medium that backs compute, to modern persistent storage, here it is: * 40 GB/s per DIMM vs 5-10 GB/s per NVMe SSD. At most one order of magnitude off, but you can pack enough disks into a computer that the throughput ratio is almost 1:1. AWS EBS is about 1 order of magnitude different here, and that is with network-attached storage. * 100-200 ns latency (RAM) vs 10-50 us (fast SSD) - about 2 orders of magnitude, but also possible to hide with batching.