Page 1 of 1

Photowall performance issues across multiple monitors

Posted: Mon Nov 30, 2015 3:47 pm
by paul1965
The other day I tried running Photowall on my PC with multiple monitors. My setup is 3 22" LCD HD monitors running on a Gigabyte GTX 960 Overclocked 4 GB GDDR5 card and one 32" LCD HDTV running on the onboard Intel HD graphics card (CPU is Core i3 3.50GHz and 16GB memory, running W10). It would launch fine but I noticed after a short time the speed between the different monitors was off, with 2 of them becoming slower than the other 2. If I relaunched GPS it would work fine for a short while, then the same thing would happen. I also noticed that after a while GPS would start to not respond, and if I tried to get into the Task Manager at that time, it would absolutely kill my PC (screen would alternate between blank and whatever window was open at the time) and I would have to do a hard reset. If I launched Task Manager first then GPS, GPS took even longer to load and still had performance issues. However looking at the CPU and memory performance I didn't see GPS was the cause as CPU and memory usage seemed to be normal.

My PC isn't the best thing out there but I don't think it's a slouch either. Am I asking too much trying run Photowall on 4 monitors or is there some setting I'm missing? Why would Task Manager impact the performance of GPS like it does?

I should also add that the folder GPS points to is on a networked PC but I don't think that would cause the issue.

Re: Photowall performance issues across multiple monitors

Posted: Mon Nov 30, 2015 3:59 pm
by gpb
Hello,
the photowall feature can be really heavy for the system, the problem is not cpu or gpu but the capability of your system to load the needed images fast enough to feed the scrolling engine. In fact on your system photowall starts at a normal speed but then it slows down, this means your system is not able to load images fast enough and the scrolling engine slows down.
If your images are stored on the local hard drive and the images size of the photowall are not too small your pc should be able to run a photowall on 4 monitors provided no other programs uses the hard disk. For example if the antivirus performs a system scan when the screen saver start probably gPhotoShow is not able to load images fast enough.

Re: Photowall performance issues across multiple monitors

Posted: Mon Nov 30, 2015 5:13 pm
by paul1965
Thanks for the quick reply. I have 2 other PC's that also run Photowall at the same time and they aren't affected, and all of my PC's are networked with each other thru the same Gigabit switch. However those other PC's are connected to just one TV easch so they don't have load a ton of images, so your theory makes sense. Would making sure each LAN card is set to full speed make any difference (rather than the default auto negotiate)?

Re: Photowall performance issues across multiple monitors

Posted: Mon Nov 30, 2015 5:28 pm
by gpb
To display the photowall on 4 monitors means the number of images to load is multiplied by 4, I don't know your system and how big are the images however even if your lan is gigabit class loading files from a server introduces delays, small but when you have to transfer tons of images they accumulate. It is also possible that the server is not able to provide the files fast enough in particular if all pc load images from the same server.
I don't think changing lan card settings could help.
Anyway from the gPhotoShow error log you can see how much time it takes to load and prepare images.

Re: Photowall performance issues across multiple monitors

Posted: Mon Nov 30, 2015 5:36 pm
by paul1965
Okay. I'll enable logging and see what it shows. Thanks again.

Re: Photowall performance issues across multiple monitors

Posted: Wed Dec 02, 2015 4:32 am
by paul1965
I haven't checked the logs yet, but doing some more testing I think this is an issue with how GPS handles system hangs or slowdowns. While I had my browser open (Firefox), Flash hung loading a page. When that happened and GPS Photowall was running, 3 of the 4 monitors had their scrolling speed cut roughly in half compared to the 4th one. I restarted GPS and all was fine until I clicked the Start button. It took around a second for the Start menu to load and during that time, 2 of the 4 slowed down again. I've checked the CPU, memory, disk and network usage by GPS and they're all minimal even when it first loads so I'm sure that's not the issue, and based on what I've mentioned above I don't think it's an issue with my systems ability to load the images. What do you think?

Re: Photowall performance issues across multiple monitors

Posted: Wed Dec 02, 2015 9:12 am
by gpb
gPhotoShow uses a thread for each monitor and another for loading images, in case of photowall the threads that scrolls pictures on each monitor should take very little cpu time since most of the work is performed by the gpu. Only the thread that load images should have a high cpu usage, when loading from a hard disk it has peaks going to 100%. If this doesn't happen the loading process is probably limited by the network, gPhotoShow doesn't handle network in any special way it uses the same functions it uses to load images from local drive. This is one of the reasons that may cause the program to hang, image loading is a single operation, gPhotoShow calls a windows function to open and decode each image if the network is busy or something goes wrong and that function takes too much time gPhotoShow simply hangs.
In addition consider that if gPhotoShow is started as screen saver it runs at a lower priority and if another program needs resources gPhotoShow may slow down.

Re: Photowall performance issues across multiple monitors

Posted: Wed Dec 02, 2015 9:29 pm
by paul1965
Thanks for the additional info...