question for rendering at high resolution

[alex321]

Hi
i m rendering at 4000 pixels X 3000 pixels.
My render buckets are left at default i.e. 48
Is it ok if i set them at 80 in order to save in render time ?

thanks

Alex

[dalomar_cg]

Re: question for rendering at high resolution

Buckets are a devious little setting. The bucket size itself will determine how much of the scene is being solved for at a given time, and therefore, will have an impact on the memory usage during the render. Smaller buckets will require less memory and larger buckets will require more. There is a certain amount of preprocessing/set up time that is required for each bucket (this is even more significant with DR, since the bucket will have to be sent to the node, as well as received once its done). So if you have a larger number of buckets (resulting from a smaller bucket size), then there will be more time spent on the "ins and outs" of the buckets.

At this point logic would say that its better to have a larger bucket size as that will make it quicker. This is not necessarily the case, since a larger bucket size will require more memory, which may entail using virtual memory which is very slow. In fact, most of the time smaller bucket sizes tend to actually yield a faster result (this is not a hard fact, but this has been my observation from when I've played around with it on a few scenes(not hires ones if I remember). Also "faster" may be something like 2%, so its not like hitting a shot of nitrous)

My own personal recommendation is to either keep the buckets at 48 or set them a little lower at something like 36. The main reason why is because setting a larger bucket size runs the risk of running out of memory, and that means either drastic slowdowns due to virtual memory or even worse crashing. Usually the last thing I want to gamble on is a hires render that I'm not going to be watching over from minute to minute. If I'm going to leave it over night I want it to be there in the morning . Any speed advances which may or may not be there (because the optimum bucket size will differ from scene to scene) are likely to be only like 5 minutes over the course of a 8-10 hr render...not worth it in my book.

[alex321]

Re: question for rendering at high resolution

Thanks Damian
as usaual your advices are a goldmine of good info
really appreciate your help

have an excellent 2008

regards,

Alex

[dalomar_cg]

Re: question for rendering at high resolution

Glad I could help...have a good new year as well.