Topic: Photosynth 1 performance

Report Abuse Report Abuse
Joscelin.Trouwborst (Over 1 year ago)
Just had a look at the process in Task Manager on Windows 8.1 while creating a new synth. Surprised to see that it is only 32-bit, uses only 28% cpu and very little of the 8GB RAM. I feel an app like this should take advantage of a 64-bit quad core with 8GB.
NateLawrence (Over 1 year ago)
An upgrade to a 64 bit synther would be very welcome, simply because it would allow the application to utilize more than 4GB of RAM during scene reconstruction (thus hopefully avoiding running out of RAM on many larger photo sets) and most serious users have been asking for this upgrade since 2008.

The amount of CPU that it uses will vary by task that is performed.
Converting input JPGs to tiled multiple resolutions can be easily parallelized to use multiple cores, as can feature detection, extraction, and matching.

Scene reconstruction, however, is more difficult to write in such a way that multiple processors or cores of a single processor can work together to form a single reconstruction (at least it still was in 2008 when Drew Steedly spoke to Channel 9) so this portion is single threaded and therefore scene reconstruction can easily soak up 100% of one of your cores, however the more cores you have, the lower percent of the whole this will be.
NateLawrence (Over 1 year ago)
While the synther being a 32 bit application limits the total amount of utilizable RAM to 4 GB at a time (and this only in situations where the user is running a 64 bit OS and has more than 4GB installed with 4GB of that installed RAM free for Photosynth at all times - meaning that on your setup with 8GB of installed RAM, other applications and files, if open at all, you will limit to use less than 4GB when combined with the amount of RAM that Windows itself is using, leaving 4GB free for Photosynth to use any time that it is open) the amount of RAM (up to that 32 bit maximum address space of 4GB) which Photosynth will actually use is determined by: 
1) how many features your photos contain and 
2) how much your photos overlap each other.
NateLawrence (Over 1 year ago)
Unfortunately, I suspect that the Photosynth team may never update the original synther again, having moved on to Photosynth 2, in much the same way that they abandoned their Direct3D viewer when they moved to Silverlight and abandoned development of their Silverlight viewer just before GPU support was added in SL5, since Silverlight itself was no longer being developed. 

At this point, I think that the original synther still being able to upload and the promise of the Silverlight viewer still being made available for original synths when the preview site replaces the main site later this year is considered a concession to long time users, rather than completely cutting us off.

I'm not sure how the synther handles Photosynth's camera database but as sensor sizes are added (like the GoPro Hero 3+ info recently added in Photosynth 2) it would be great if the synther could pull down the most comprehensive list of camera parameters each time that a new synth is begun.