I've been evaluating PhotoScan for work. In playing with some small jobs I see it rather quickly take nearly all, or all my memory (first time I've seen all 24 gigs in use). Once I tried a larger job it quickly filled the pagefile (which after some more reading would have been better done with height-field instead of arbitrary, but that's another topic). So based on this, it looks like I'm going to need to get more ram first. Which about leads me what I've got, and what to look at upgrading.
Right now I've working with a HP Z440 with a Xeon E5 3.5 GHz, 24 GB ram, and a Nvidia Quadro K2200.
My thoughts are as follows: Ram first, because hitting the page file is like hitting a runaway truck ramp. What could be slow or really slow processing basically stops. I'm thinking that 128 GB would realistically cover me, or maybe 192 (based off the Agisoft paper on memory requirements), especially looking at the possibility of a higher resolution UAV camera in the future. In the event that's not enough, or I end up with a job even larger that needs page file space, is it possible to set up a PCIe SSD to be used as a pagefile? That would be better performance in that event than a regular 7200 RPM HDD, right?
Next, the graphics card. I've got 2 6 pin plugs and 1 open PCIe x16 slot. Reading though other posts on this forum, its pretty clear that for this application the gaming type cards beat out the workstation type cards dollar for dollar. The machine this goes on also gets used for rendering stuff, so I don't see losing the quadro as an option. Looks like the flagship cards would require an upgrade to the PSU as well. Does PhotoScan handle differing video cards like that, or would I be best running with just the gaming type card enabled? Dollar for donuts do the modern flagship cards offer enough performance over an older card that the existing PSU can handle to justify the cost and additional upgrades? Also, with all the bitcoin hype, I've been reading about the gaming cards being run hard for a year or two and then they're basically toast from being bear up from all that use. Would a quadro offer longevity in this situation at the expense of some performance?
Finally, the CPU. I'm not seeing much of a need to upgrade here. Yes there is room for an upgrade (or a z640 so I can get 2 of them), but unlike RAM, a slow CPU won't slow it to the point of unusability. But then I'm wondering where does the GPU/CPU balance sit? Is a better CPU going to help that much, or is just going to mean I start processing and let it run over night? Because at the end of the day, the software isn't my whole job, and if I've got a 2nd workstation tied up processing it while I do other work, that isn't going to ruin my ability to do work.