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Not sure if this is the right tag for this question. If not, please advice which is the right one.

See this QuickBench example run here where there is no output when multithreading is needed.

https://quick-bench.com/q/XW3X12SejvDrZnqcKDQsiN5SoPI

Guess QuickBench doesn't support multithreading so there is no output when a benchmark is requesting multithreading.

enter image description here

visitor99999
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  • You can build & run the benchmark locally, in which case you can use any compiler / linker options you wish. The quick-bench.com service is for really simple benhmarks, IMHO. – zkoza Jul 12 '21 at 21:35
  • So you agree that the quick-bench has its limitation in this example? I can run benchmark locally later when I have a chance. – visitor99999 Jul 12 '21 at 21:37
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    I don't know. For a "real stuff" i run benchmarks locally. – zkoza Jul 12 '21 at 21:54
  • I wouldn't be surprised if they don't allow more than 1 thread on quick-bench.com. It must already cost a decent amount of money to pay for cloud CPU time to run single-threaded benchmarks for free in a public-facing site, with a benchmark interval long enough to somewhat hide noise. – Peter Cordes Jul 13 '21 at 05:36
  • not sure how these online compiler/benchmark tools work. Sounded like you have some insights on their operation models. By the way, I ran the test on Visual Studio, it crashed – visitor99999 Jul 13 '21 at 17:16
  • They sandbox the code you're benchmarking so you can't e.g. use their CPU time to mine cryptocurrency, send spam, or do DoS attacks. I know https://godbolt.org/ runs on AWS instances, but I don't know about quickbench. Matt Godbolt wrote a blog a while ago about how his site works: https://xania.org/201609/how-compiler-explorer-runs-on-amazon (Although that might have been before they added the ability to execute compiled binaries. But even without that, you need to assume that running something as complex as GCC on untrusted input is basically insecure and could lead to remote-code exec) – Peter Cordes Jul 13 '21 at 21:33
  • thx for the link! – visitor99999 Jul 20 '21 at 18:43

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Re-ran the same test code on a Linux machine in which a Google Benchmark is installed. The code works fine there. So confirm quick-bench doesn't support multithreading.

visitor99999
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