The important thing when analyzing performance is to have a valid benchmark before you start. So let’s start with a simple JMH benchmark that shows what our expected performance after warmup would be. One thing we have to consider is that since modern operating systems like to cache file data that is accessed regularly we … Read more
In fact, it already exists, as part of the pragmatically named memory_profiler package: In [2]: %memit np.zeros(1e7) maximum of 3: 76.402344 MB per loop More info at https://github.com/pythonprofilers/memory_profiler#ipython-integration Edit: To use this, you first need to load it as an IPython extension: %load_ext memory_profiler To make IPython always load the memory_profiler extension upon startup, add … Read more
Summary (notable points): Two packages benchmarked (one with 78 compilation units, one with 301 compilation units) Traditional Compiling (Multi Unit Compilation) resulted in a 7% faster application (in the 78 unit package); no change in application runtime in the 301 unit package. Both Traditional Compiling and Header-only benchmarks used the same amount of memory when … Read more
I participated in the beta evaluation of the BDB SQLite code and one of the things I tried to get a handle on was the performance difference. At this point, I cannot publish exactly what I found until I have at least one other person evaluate my code, run the tests, and confirm the numbers … Read more
In the end it all comes down to correct cache handling… symfony or PHP in general IS slower than other languages or frameworks thus providing you with the tools to create rich, secure and testable web applications really fast. If you use a reverse proxy like Varnish and ESI ( edge side includes ) and … Read more
I wrote Benchmark.js, which jsPerf uses. “ops/sec” stands for operations per second. That is how many times a test is projected to execute in a second. A test is repeatedly executed until it reaches the minimum time needed to get a percentage uncertainty for the measurement of less than or equal to 1%. The number … Read more
Jmeter tells you how long each request actually took. AB just does some very basic math to get the overall average. So, the direct answer to your question is that jmeter gets it right and ab just makes a rough guess by giving you the mean across everything. But, sure, if you put the two … Read more
This is a classic java benchmarking issue. Hotspot/JIT/etc will compile your code as you use it, so it gets faster during the run. Run around the loop at least 3000 times (10000 on a server or on 64 bit) first – then do your measurements.
NB: The high memory usage issue is a bug in the GHC RTS, where upon stack overflow and allocation of new stacks on the heap it was not checked whether garbage collection is due. It has been already fixed in GHC HEAD. I was able to get much better performance by CPS-converting ack: module Main … Read more
By looking at the source code we find these timing points: apr_time_t start, /* Start of connection */ connect, /* Connected, start writing */ endwrite, /* Request written */ beginread, /* First byte of input */ done; /* Connection closed */ And when request is done some timings are stored as: s->starttime = c->start; s->ctime … Read more