Am 04.09.2011, 19:01 Uhr, schrieb Christian Köstlin <christian.koestlin@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.