Processing time for DSLR subs...

[RobertM]

I've been processing some DSLR images with maximdl and I'm looking at ways of speeding this up.

I did about 70 last night and that took about 20mins which is a long time to wait, file format seems to make a lot of difference.  MaximDL is storing as FITS format at the moment but I'm not sure this is ideal - it certainly isn't space wise (72Mb each).

For comparison, how long does your PC take to stack DSLR subs and what file format are your subs stored as (FITS/RAW/TIFF or something else... jpg ) ?

Has anyone any experiences of using a ramdisk with windows xp ?

Thanks
Robert

[Rocket Pooch]

If you think Maxim is slow try Astro Art or even worse DSS!

I could do a fits comparison in AIP but I know its a lot quicker than the above.

[mickw]

Robert isn't your laptop a lowish spec second hand jobbie ?

Would it be better to transfer all the captured files onto a faster machine for processing - or get a new laptop with/without ramdrive

[RobertM]

Yes, true Mick but the timings are on a machine with a core 2 quad cpu, 4gb ram and a 256Gb SSD.  I reckon the laptop would have a high probability of hardware failure before it finishes stacking that many subs !

A ramdrive might be a way to go as CPU % is quite low during stacking (probably because I'm processing debayered fits files)...  70 x 72Mb = 5Gb hmmm... I'm a few bytes short on the RAM side.  The motherboard can take 16Gb but then that's not much use without going for a 64bit o/s - 64bit Fisher Price (Windows 7) am I ready for that !

[Mike]

I don't see how a RamDrive would be quicker than SSD.

[mickw]

Sorry Robert, I thought you were trying to do the lot on the baby one.

Apparently ramdrive does have the edge over SSD possibly something to do with the interface.
I think you would need to up the ram though to make better use of it - and you don't need to go 64 bit

An example -
http://www.superspeed.com/desktop/ramdisk.php

[Rocket Pooch]

Yes, true Mick but the timings are on a machine with a core 2 quad cpu, 4gb ram and a 256Gb SSD.  I reckon the laptop would have a high probability of hardware failure before it finishes stacking that many subs !

A ramdrive might be a way to go as CPU % is quite low during stacking (probably because I'm processing debayered fits files)...  70 x 72Mb = 5Gb hmmm... I'm a few bytes short on the RAM side.  The motherboard can take 16Gb but then that's not much use without going for a 64bit o/s - 64bit Fisher Price (Windows 7) am I ready for that !

Robert,

Have a look at two things, each core and also the memory usage, if all the core memory is used and the system is paging then your stuffed because its trying to write one massive file.  Also if you use a ramdisk you could either use it for the working file, that will be quicker, but you will be taking memory away from the kit.

If you have an SD card slot pop one in and use that as a working drive/.
Chris

[Rocket Pooch]

Hi Rob,

Just done 96 QSI images AIP stacked adv, processor 50% memory 180mb time 12 minutes, this is with my browser and email client etc running.

Laptop Dual Core 1.5ghz 4GB ram 80gb hard drive

Sigma stacking will double the time.

Chris

[RobertM]

Phew, just got home after well over 3hrs on three trains !

Just stacked 100 FLI images which should be the same size as yours using sigma clip with a sigma factor of 3 and that took 18 mins.  Interestingly cpu hovered around the 18-35% mark with a few spikes at 65% and ram used never went over 1.6Gb (XP recognises 3.4Gb).  I suspect maximdl is not multiprocessor friendly so doesn't really use more than 25% directly and that it's writing swap files out to the SSD.

Will try a ramdisk for temporary files next and see how I get on, they can be up to 1600Mb/s for read and 1200Mb/s for sequential writes so would be good for those type of temporary files.  It should make better use of the CPU and also save wearing out the cells in my SSD!!!

Robert