Hi everybody,
On the same server, I have installed a fresh copy of coppermine and zenphoto. I notice for a while that the loading time of zenphoto is 2-3 times longer than Coppermine. Loading time: coppermine (average 105 ms) and zenphoto (321 ms). Is it normal ? Can I do something to reduce the loading time of zenphoto ? I like zenphoto and I am already merging old coppermine accounts to zenphoto, but I do not want to regret it later.
Thanks for your help!

What you see is a delay when Zenphoot creates the sized images/thumbs on your theme the first time and caches them. This happens only once. I am not familiar with Coppermine but maybe it does create them on upload already. In short Zenphoto has no fixed image sizes for the front end, the theme defines which sizes it uses.

Please read here: http://www.zenphoto.org/news/caching

The ZenPhoto and Coppermine I have newly installed do not contain any images. I have installed these two scripts using softaculous on my server. That's it! No images nor any configuration.
In my other server, I have installed ZenPhoto and populated it with now more than 1,000 images. I notice the loading time (I use IpHostMonitor) was not as fast as Coppermine.
I tought it was because of the number of images that slow down the loading time.
Any clue ?

Zenphoto does do a lot of filesystem work, to enable it to detect new images and albums on disk without having to resort to a manual upload process. It's part of its design that it mirrors the albums on disk. Because of this, it can be slightly slower per page, but it is generally fast even for very large albums.

I haven't looked at the backend PHP scripts in a while, but it could be time for some optimization. However, 320ms for an album of over a thousand images does appear reasonable.

Is there a particular case for which you need the speed? Would page caching be sufficient to handle extra load or decrease load times?

There is always room for optimization. But it should all be faster after the images are cached in sizes as needed.

Other systems like WordPress do create standard sizes while uploading. We don't as there are no standard sizes being theme dependent. Default is creating them on the fly. The more images and the larger they are the slower it might be initially. Which depends on the server naturally, too.

Dependening on the theme it is possible to pre-cache images using the cacheManager plugin but the theme used must be setup for it. Additionally we have of course a static_html_cache plugin for page caching itself. All noted on the link I posted as well.

Hi,
A little bit more stats about ZenPhoto vs Coppermine ...
http://destilino.com/divers/zenphoto-coppermine-performance-Nov2014.jpg
As a stated in a ealier post, these are fresh installation, no images uploaded nor any configurations. It helps to compare both scripts.