4 ms·
I mean that’s really close. I always thought of RAM as multiple orders of magnitude faster than disk. Within 3x of speed is pretty excellent. (though, I guess
by californical 5y ago
I mean that’s really close. I always thought of RAM as multiple orders of magnitude faster than disk. Within 3x of speed is pretty excellent.
(though, I guess this doesn’t give us any latency info, just throughput. I’d expect RAM latency to still be faster)
- nh2 5y agoI would not take this benchmark to draw general conclusions. The spinning disk result is only 10x slower than RAM. But a spinning disk's throughput is 100-1000x less than current RAM, and for latency it's even worse. Similarly, the other factors in the benchmark graph are way off their hardware factors. This benchmark is measuring how one specific program (the Haskell Compiler compiling ShellCheck) scales with faster memory, and the answer is "not very well".
- koala_man 5y agoThe overwhelming majority of access would still happen in the 2GB RAM the benchmark has. The disk is only hit to stash or load overflowing pages, not on every memory access. That's why it doesn't mirror the hardware difference between DRAM and disk.
- nh2 5y agoThat makes sense, thanks!
- koala_man 5y agoAuthor here. Keep in mind that most access in the swapping case is still RAM, so we can't just say that there's a 3x difference between DRAM and NVMe flash. I originally tried running the test with only 1GB RAM, but killed the job after 9 hours of churning.