P: Make use of extra cores to process multiple photos in parallel

There is a fine line in resource management ... Not all users have the same desires and/or requirements ...

Sometimes I return from an event and need to post 4,000 to 6,000 images to my online shopping cart ASAP as time is money in getting the the pictures in front of potential customers ... other times I only need to export a few dozen images ... while I move on and perform other tasks ...

I agree with Victoria that allowing the option, based upon the current workflow circumstance would be the most appropriate method ... it would be the best of both worlds ... mainly because it would allow the user to be in control, not an arbitrary decision of the underlying code ...

Yeah, they've left it not maxed out, so that you can continue working while the export runs in the background, but a 'turbo export' checkbox in the Export dialog would certainly get my vote.

Report:

I have just tried the manual parallel processing method provided by Butch_M.

By exporting 56 photos in one go, it took 125 seconds
By manually select 30 photos export first and immediately select the remaining 26 export next, it finished in 100 seconds.

That's about 25% speed increase and that is a lot!

I believe if this can be done within the software it could be even faster.

Hi Butch_M,

Thanks for the suggestion! Yeah, this method definitely would help. I will try that next time.

But I also would like this could be built into the Lightroom export engine as well, if possbile.

Scott Kelby offered a tip in a video some time back that you could save time and invoke more resources by exporting in simultaneous batches ...

Say you need to export 300 images to jpeg to upload to the web ... select 150, then export ... immediately select the remaining images and export ... the long hand method to multitasking export ...

Hi John,
Thanks for the reply.

However, I have Lightroom 4.1 running with 16GB ram on a Windows 8 64bit system. So I don't think memory is a bound here for just 50 photos. And my catalog, raw cache files and original raw are stored on SSD drive and I guess there is no i/o bound here as well. But just try to eliminate these cause, I will try to use the Resource Monitor the monitor the CPU/Memory/Disk usage during export next time when I doing the export.

BTW, I have tried to turn off HT for my CPU and I got almost exactly same amount of time used for exporting 50 photos. So Lightroom is actually not using the extra threads provided by the CPU at all.

I suspect the export process is memory and (to some extent) i/o bound, not CPU bound. The assumption based on looking at task manager that 100% utilization would mean more ability to export is not based on real observations.

Not only is the task manager a very rough and not very accurate picture of the work your computer is doing, it is not in the least predictive. And, like I said, it depends if the problem at hand (i.e., exporting renditions) is CPU bound or not.