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APP Processing Time + Drizzle

Processing Drizzle Stacking Deep Sky
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schmaks avatar
schmaks avatar
Hi there,

I am in the process of integrating around 1,000 subs, with 2x drizzle being applied and it has been running for nearly 24 hours and isn’t yet half way done.

I wasn’t expecting it to take this long since I have had integrations of around 500 subs take far less time; so I am curious to know how drizzle affects your processing times?

Thanks!
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schmaks avatar
schmaks avatar
Another note: I have "create drizzle/MBB wight map" selected. Might that be affecting the processing time as well? I am not sure exactly what that does nor if I need it.
GoldfieldAstro avatar
GoldfieldAstro avatar
I'm running APP on a 2019 iMac and find that if I walk away, after a while APP goes into kind of a "sleep" mode where it takes at least 10x longer to do anything. I never leave APP alone, always doing something on the computer or at the very least periodically move the mouse or push a random button on the keyboard.
Ian Dixon avatar
Ian Dixon avatar
I'm running APP on a 2019 iMac and find that if I walk away, after a while APP goes into kind of a "sleep" mode where it takes at least 10x longer to do anything. I never leave APP alone, always doing something on the computer or at the very least periodically move the mouse or push a random button on the keyboard.


i would agree with this!
schmaks avatar
schmaks avatar
Thanks, I'll try this out with future integrations and see how it works.
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matthew.maclean avatar
matthew.maclean avatar
It could also be running out of available RAM? I don’t know for sure how APP manages it but I think the drizzle integration uses a lot more. If it has to write a lot of temporary files to disk, that is vastly slower.
GoldfieldAstro avatar
GoldfieldAstro avatar
Our experience has been that when drizzling there isn’t much of a RAM requirement increase but there is significantly more temporary files needed.

We have 128GB of RAM and when drizzling more than 100 images from an ASI094 (36.6mp OSC) it runs out of RAM but has a hard crash. If it’s just taking a long time then it doesn’t sound like a RAM issue.
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John Favalessa avatar
John Favalessa avatar
Try turning off all power management options on your iMac.   That works for me with APP.  I noticed if my screen goes to sleep APP pauses.
dkamen avatar
dkamen avatar
1000 subs is not a small working set, especially if it is DSLR-sized subs and you are using full or reference integration as opposed to a crop.

You will see a .dat file in your working directory, that's where APP puts all the temporary files for the stuff it's doing (calibrated, registered, normalized, locally normalized, integration buffers). Its size will give you an idea of how large is its working set smile

I believe Drizzle in particular requires one copy per sub, that is each sub is "drizzled" independently and the resulting, larger images are integrated as per the other integration parameters. This can be very demanding.

Cheers,
Dimitris
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Sauro Gaudenzi avatar
Sauro Gaudenzi avatar
I App I have installed it for a few days and I have for the moment the test for 30 days,I did a test with 30 shots of the region of Mirfak (Constellation of Perseus ),10 dark,10 flat,10bias,to reduce the waiting time to have the final photo processed I minimized the procedure for the integration phase,it seems that the times are reduced , take this consideration with springs because I've been using this program for a few days, I still have to study it well
Paolo Manicardi avatar
Paolo Manicardi avatar
APP tell you how much ram / cpu is using, and you can also check by windows task manager
before integration APP indicate also of much hard disk memory will be needed during integration, and you can also use task manager to check how much HDD writing is done in real time.

Anyway as dkamen have said, 1000 subs is a real large set of image and can be very demanding, depending on sensor resolution and your pc power.
What size are your images? and the spec of your pc?
Simon Todd avatar
Simon Todd avatar
It could also be the speed of your storage device where APP is using (It asks you when starting), with Drizzle, APP needs to dump a lot of stuff to disk, and a slow disk will negate a slow performance.