Michael Smith wrote:
>
> On May 23, 2007, at 11:16 AM, Brett George wrote:
>>> On May 23, 2007, at 11:07 AM, Brett George wrote:
>>>
>>>> I am using memcpy on an x86 machine and finding it to be quite slow
>>>> compared to other optimised routines.
>>>>
>>>>
>>>> I am moving 16384 words of 32-bit floating point data and it's taking
>>>> around 49us.
>>>>
>>>
>>> Your mention of floating point leads me to verify whether you're talking
>>> about the memcpy in the kernel or the one in userland?
>>
>> This is a floating point library in the kernel.
>
> Those two terms ("floating point" and "kernel") just don't belong together.
Maybe, but this is an audio driver and with good reason it's the
standard way they work.
> However, bcopy in both the kernel and userland are quite heavily
> optimised. My math says:
>
> % expr ((16384 * 4) / 0.000049) / 1024 / 1024 / 1024
> 1.24561543297
>
> i.e. a bit over 1.2GiB/sec. Which hardware are you running on, and how
> is it configured?
I'm using a MacBook Pro (2.33GHz Core2Duo) with 2GB RAM (running
10.4.9). Please let me know if you need more information.
Thanks,
Brett.
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