4 ms·
Lookup tables aren't necessarily faster these days for a lot of things when using low-level languages, but it would have been interesting to see the comparison
by mmastrac 2y ago
Lookup tables aren't necessarily faster these days for a lot of things when using low-level languages, but it would have been interesting to see the comparison here.
- adhoc32 2y agopretty sure a memory access is faster than the methods presented in the article.
- dist-epoch 2y agoHitting L2 is more than 3-4 cycles
- retrac 2y agoAccess to main memory can be many many cycles; a short routine already in cache may be able to recompute a value more quickly than pulling it from main memory.
- Retr0id 2y ago64K is enough to fill L1 on many systems
- PhilipRoman 2y agoDepends also heavily on the context. You pay for each cache miss twice - once for the miss itself, and next time when you access whatever was evicted during the first miss. This is why LUTs often shine in microbenchmarks, but drag down performance in real world scenarios when mixed with other cache bound code.
- ryao 2y agoAn uncached random memory access is around 100 cycles.