Am 04.09.2011, 19:01 Uhr, schrieb Christian Köstlin
<christian.koest...@gmail.com>:
On 9/3/11 7:53 , dennis luehring wrote:
Am 26.08.2011 19:43, schrieb Christian Köstlin:
Hi guys,
i started the thread:
http://stackoverflow.com/questions/7202710/fastest-way-of-reading-bytes-in-d2
on stackoverflow, because i ran into kind of a problem.
i wanted to read data from a file (or even better from a stream, but
lets stay with file), byte-by-byte. the whole thing was part of my
protobuf implementation for d2, and there you have to look at each byte
to read out the varints. i was very proud of my implementation until i
benchmarked it first against java (ok ... i was a little slower than
java) and then against c++ (ok ... this was a complete different game).
after some optimizing i got better, but was still way slower than c++.
so i started some small microbenchmarks regarding fileio:
https://github.com/gizmomogwai/performance in c++, java and d2.
could you help me improve on the d2 performance? i am sure, that i am
missing something fundamental, because i thing it should be at least
possible be equal or better than java.
thanks in advance
christian
i would change the test szenario a little bit
1. use a ramdisk - so stuff like location on disk, fragmentation, driver
speed will reducued down to a little bit of noise
2. make your szenario much bigger
3. would be interesting to see for example to cumulated every 1000
benchmarks-steps or something like that - to see caching coming in etc.
running 10.000 times
time for 1. 1000 steps xyzw
time for 2. 1000 steps xyzw
time for 3. 1000 steps xyzw
time for 4. 1000 steps xyzw
overall time ... xyz
...
good point ...
will see if i can adapt the tests...
cK
-release -O -inline -noboundscheck is the options set for D2. In D1
-release included -noboundscheck.
