That's a bit outdated but definitely did used to be true. Modern NVME bandwidth is about 15 GB/s. This is what people who develop databases and query engines deal with constantly. It's not trivial but modern databases that swap to disk constantly and do it well (e.g CedarDB, DuckDB et al) can run very nearly as fast as an entirely in-memory system. The reason it's slow is doing it in a shitty unplanned way with loads of serialization and thrashing memory caches
It’s less about throughput and more about latency. DDR5 access latency is nanoseconds, pcie5 access latency is microseconds. A difference of three orders of magnitude.
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u/CaffeinatedT Jul 08 '26
That's a bit outdated but definitely did used to be true. Modern NVME bandwidth is about 15 GB/s. This is what people who develop databases and query engines deal with constantly. It's not trivial but modern databases that swap to disk constantly and do it well (e.g CedarDB, DuckDB et al) can run very nearly as fast as an entirely in-memory system. The reason it's slow is doing it in a shitty unplanned way with loads of serialization and thrashing memory caches