Le 10/02/2020 à 20:15, Mirfaelltkeinerein a écrit :
> "jr" <cre### [at] gmailcom> wrote:
>> hi,
>>
> 
>>
>> are you sure about the resolution being the .. culprit?  at least one user
>> renders (much) larger images with no mention of ill-effects.
>> <http://news.povray.org/web.5ceaeabd5e75640e3c1c78400%40news.povray.org>
>>
>>
>> regards, jr.
> 
> No, not at all. But the problem manifested itself at higher resolutions and
> vanishes at lower ones.
> 

The bottleneck is a single thread doing all the I/O for the temporary
storage on disk of the rendrered pixels until the whole image is ready.

You have a hord of threads doing the computation of each block, feeding
a queue that is processed by a single thread T.
When the resolution is small enough (see my other reply), T stores the
blocks in memory (usually fast enough).

BUT when the resolution is bigger than the setting, thread T must
perform disk I/O (and from the file point of view, it is really random
access, and can be very bad with Windows file system). As T is
overburden, the rendering threads are starving to get new blocks
(otherwise, the queue from them to T would explode).

try adding +MI3210 to the option and see per yourself.

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