Requesting tips for devoting RAM + cycles to photogrammetry

[Nathanael]

I do not know what sort of computers the rest of you have access to, but for me upgrading my system is an impossibility at the moment. The nicest PC I have only has 4GB of RAM, so I am very constrained in how much I can tie together per synth or Bundler collection.

I know that the synther is only a 32-bit app and therefore even in 64-bit versions of Windows, it should only be capable of consuming a maximum of 4GB of RAM, but of course in my case the OS is using some of the 4GB that I actually have in order to run the computer. With PMVS being as RAM hungry as it is, I get the feeling that this might still be useful to those who have a considerably larger amount of RAM.

I have thought before that it would be great to have some sort of way to easily put your computer into 'synthing mode', if you will, that would close all processes and underlying operating services/daemons that were unnecessary to complete the computer vision - some way to simply express to the OS, "This synther process is literally the only thing that I want to run. Give it every shred of RAM that is not necessary for keeping Windows alive and responsive.".

In Photosynth's case, network access is a must, but outside of that I'm not entirely sure what all is good or safe to stop.

I run Windows 7, but I would love to see tutorials for Windows 7, Windows Vista, Windows xp, OSX, and specific distributions of Linux.

My concern is only that when I boot into my desktop, currently, something like between 34% to 40% of my RAM is immediately consumed by the operating system just sitting there idling, even after I kill the Explorer process once and relaunch it.

I know that disabling Windows Aero is a good RAM saver. I believe I tried just starting up in Safe Mode with Networking once, but I don't believe that Photosynth wanted to run when I did, so I'm not sure what it was missing then or even whether that is typical results.

For MacOSX, I've never even tried to run Bundler or CMVS/PMVS, but I have absolutely no idea how to manage system resources on OSX at all.

In any case, if someone has deep knowledge for how users such as myself can devote every possible scrap of RAM that we have to Photosynth, Bunder, etc. during scene reconstruction, I would love to see this sort of thing move forward as I think it could benefit users across all operating systems who cannot afford more RAM or a new motherboard to install more RAM.

To some degree, this heads into simple system maintenance territory - using SysInternals Autoruns to stop Java, Flash, iTunes, Adobe Reader, etc. etc. speedlaunchers from running at startup, but I don't know that I would always want to boot my desktop in such a stripped down state that I would like to have to create the largest reconstructions with.

Ideally, I would like a simple solution that could toggle off or restart the computer with nothing but photogrammetry essentials when desired, but then go back to a normal startup by default.

Lacking that, I'll happily take a tutorial that simply lists everything that ought to be running for best performance of the synther/Bundler/etc. It's easy to just go switching off services in Windows and assume that they aren't necessary, but I might end up turning off something that is not essential to Photosynth operating, but would benefit me - some sort of hard disk management or something.

In any case, I await your advice and tutorials.

P.S. Can anyone tell me with any certainty what the maximum amount of RAM is that is given to each 64-bit process on different operating systems? I recently read something which I took to mean only 8GB were given per 64-bit process. If I'm understanding correctly, this would mean that even if I had 192GB of RAM for my 64-bit version of Windows, PMVS2 could still only consume 8GB of it itself, unless it were to spin up multiple processes. Am I understanding this correctly?

Update: Thanks to Kjellis85, I see that what I was remembering as 8GB of virtual memory per 64bit app was actually 8TB per app! 8TB of RAM... if only it were possible before the decade comes to a close! ツ

[Kjellis85]

Well, I don't know how much more you would gain in quality by increasing the amount of memory running on win 7. Even without running aero and all other redundant stuff, your still only going to be able to free about 500 Mb, at best. Since you are not going to be able to predict the amount of ram each set of photos will require, at least at a <50 Mb accuracy, I don't believe it would be worth the trouble. But that doesn't really matter, cause if you have 4Gb and the system is idle at 30-40% you should have plenty for the 2Gb limit for the synther. Depending on what you are looking to do, I would recomend any of the free online services. They are fast and reliable, and SFM CMP service is running a bundler setup, so if that is your goal I would recommend that.

Here is a list over all the different win os ram limitations/capabilities: http://msdn.microsoft.com/en-us/library/aa366778(v=vs.85).aspx

[Nathanael]

I have been under the impression that the synther has the IMAGE_FILE_LARGE_ADDRESS_AWARE flag set in its header, based on the first few lines of output in the log files, which would mean that on 64-bit systems, it should be able to consume 4GB, rather than the typical 2GB that 32-bit apps can use under Windows by default. If I am mistaken, then you are right: I still have over 2GB of RAM free, however if I am right, then short of me being able to install enough physical RAM that 4GB is free for the synther or more for Bunder/PMVS, then I am still interested in knowing how much of the OS I can turn off and still maintain an optimal environment to run the largest photo sets.

I love how simple it is to shoot good coverage for objects to reconstruct with these tools, however the amount able to be reconstructed as a single object is somewhat dismaying to me. Even using PhotoCity, I was only able to push three of my mid-sized synths into a single reconstruction before the set slowed down and repeatedly crashed the process on the server.

ARC3D and Hypr3D both recommend far smaller photo sets than what PhotoCity can handle and I have experienced complete failure with Project Photofly with a simple set of 130 photos.

I admit that I have yet to see or hear of this SFM CMP service, so I'll look into that, but I expect similar results.

[Kjellis85]

My experience with CMP SFM is that they generate very good synths from large sets (150+ pics, 5M vertices 10M faces) without a hitch. Two things you should know; you should resize your images to around 1600 or so for the service to run smooth, or run at all, depending on the size of the set. The other issue is the output you recieve, a zipped bag with all the depthmap files, camera.wrl, delaunayVertices.wrl, inline_cameras_delaunayVertices.wrl, inline_cameras_meshColored.wrl and the meshColored.wrl. This is only for the multireconv4, but I assume it is much the same for the other ones. The delaunayVertices.wrl is similar to the .ply output from synthexporter, but without colour info.