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From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-11-23 09:09:09


Matthias Troyer wrote:
> On Nov 23, 2005, at 2:42 PM, Peter Dimov wrote:
>
>> David Abrahams wrote:
>>> "Peter Dimov" <pdimov_at_[hidden]> writes:
>>>
>>>> I'm not sure that there will be such a major speedup compared to
>>>> the naive (1).
>>>
>>> Why the doubt? We've measured.
>>
>> Out of curiosity, what did you measure?
>
> The 10x speedup that was measured was for using the serialization
> library, with and without save_array hooks to (de)serialize a
> std::vector<double> and a double[] into a binary archive, both into
> memory buffers and onto disk. The codes were posted with the message
> that started this thread. To quote just one number, the CPU times
> required to write 10 million double into a file were 4.12 and 0.37
> seconds respectively.

Oh, I'm not disputing that at all. I've observed a similar slowdown when
std::vector<unsigned char> iterators changed into non-pointers, bypassing my
optimized overload. :-)


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