4 ms·

These are my results on an (admittedly old) Intel i3-2120 CPU @ 3.30GHz. Compiling both programs with -O3: ojc_parse_str 1000000 entries in 3607.615 mse

These are my results on an (admittedly old) Intel i3-2120 CPU @ 3.30GHz. Compiling both programs with -O3: ojc_parse_str 1000000 entries in 3607.615 msecs. ( 277 iterations/msec) simdjson_parse 1000000 entries in 418.997 msecs. ( 2386 iterations/msec) and might as well throw in my own parser... uj_parse 1000000 entries in 1959.731 msecs. ( 510 iterations/msec) The -O3 seems to make a large difference for simdjson.

peterohler 6y ago
Shockingly different. The -O3 option made hardly any difference with OjC but more than a 10x difference with simdjson. I'll be removing the claim from the OjC readme. Thank you for being civil with your reply. Much appreciated.
- jkeiser 6y ago
  What I've learned from this (as a simdjson author) is that we need to update the quick start in the README to have -O3. I was so psyched about the fact that we now compiled warning-free without any parameters ... that I didn't stop to think that some people would go "huh I did what they told me and simdjson is slow, wtf." Because we evidently told you to compile it in debug mode in the quick start :) simdjson relies deeply on inlining to let us write performant code that is also readable. Sorry to have sent you down a blind alley! One thing to note: if you want to get good numbers to chew on, we have a bunch of really good real world examples, of ALL sizes (simdjson is about big and small), in the jsonexamples/ directory of simdjson. And if you want to check ojc's validation, there are a number of pass.json and fail.json files in the jsonchecker/ directory.
- glangdale 6y ago
  The structuring of simdjson is considerably easier to read if we rely on -O3. In order to get the same performance at lower levels of optimization we need to do a lot of manual things that make the source code quite difficult to read and work with.

peterohler 6y ago

Shockingly different. The -O3 option made hardly any difference with OjC but more than a 10x difference with simdjson. I'll be removing the claim from the OjC readme. Thank you for being civil with your reply. Much appreciated.

jkeiser 6y ago
What I've learned from this (as a simdjson author) is that we need to update the quick start in the README to have -O3. I was so psyched about the fact that we now compiled warning-free without any parameters ... that I didn't stop to think that some people would go "huh I did what they told me and simdjson is slow, wtf." Because we evidently told you to compile it in debug mode in the quick start :) simdjson relies deeply on inlining to let us write performant code that is also readable. Sorry to have sent you down a blind alley! One thing to note: if you want to get good numbers to chew on, we have a bunch of really good real world examples, of ALL sizes (simdjson is about big and small), in the jsonexamples/ directory of simdjson. And if you want to check ojc's validation, there are a number of pass.json and fail.json files in the jsonchecker/ directory.
glangdale 6y ago
The structuring of simdjson is considerably easier to read if we rely on -O3. In order to get the same performance at lower levels of optimization we need to do a lot of manual things that make the source code quite difficult to read and work with.