[MINC-users] MINC 2 api and RAM/HD access

[Vladimir S. FONOV]

Hello,

I don't think that anything you will do using MINC2 api will get you
close to the performance of accessing float[x*y*z*t] memory array.

On Sat, Sep 15, 2012 at 8:27 AM, Soren Christensen <sorench at gmail.com> wrote:
> Thanks to all!
> From local drive a call to miget_voxel_value_hyperslab takes me about
> 500ms - that is for a 512*320*12 short buffer lookup from the 512 512
> 320 12 matrix. This is noticeable and I am looking for half of that.
>  Interestingly putting it in /dev/shm seems to make no difference. I
> suppose the OS may be caching the file in RAM even if it is on the
> drive?
> The file is not compressed so nothing to gain for me here unfortunately.
>
> The only thing I can thing of to speed it up further, is if the
> reordering can be optimized - I suppose for certain reorderings longer
> blocks can be copied at once, but this may be exploited already and I
> am not even sure if there is any gain to be won here - any ideas on
> this?
>
> (The t-x-y lookup is 3ms, the t-x-z 252ms and finally t-z-y  is 519ms.
> I assume y-z-t is the slowest since there is a jump for every voxel
> read, whereas the two other "views" have larger continuous memory
> blocks - can anyone confirm?)
>
> Thanks again,
> Soren
>
>
>
>
>
>
>
> On Fri, Sep 14, 2012 at 7:21 AM, Andrew Janke <a.janke at gmail.com> wrote:
>> I'll second this. The advantage is that you let the kernel do all the
>> hard stuff.
>>
>>
>> a
>>
>> On 13 September 2012 17:35, jon pipitone <jon.pipitone at utoronto.ca> wrote:
>>> One far less glamorous way we've dealt with improving access speeds is to
>>> move images onto a ramdisk (e.g. /dev/shm) and manipulate them there
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-- 
Best regards,

 Vladimir S. Fonov ~ vladimir <dot> fonov <at> gmail <dot> com