We are trying to upgrade from v2.24 to the new v4.03. The new version is very slow with page load times of 5 to 10 seconds which is unacceptable. Here is what we have tried so far…
We turned on redis
We turned on the amazon CDN
We put lots of support tickets in.
Our site has 2 servers but dual hex core with 32G of RAM and a RAID 10 SAS drive setup. The web server is on one server and mysql is on the other server. Plenty of back end speed.
I can't figure out why the site is so much slower with the new version and thought maybe someone else out here would have a better idea than me.
Turn off Searchanise and you will see a dramatic difference too. We are using it temporarily in our store but will probably not for long. I am looking at one search and trying to find another one I found once but can't find again. I think shippingkit.com may be updating there search so I may wait for that. Either way Searchanise just needs some work, IMHO. To be honest, I'm just not the biggest of my search residing off my server.
I'm not for sure if 4.1.2 is good enough to upgrade to yet or not, but we did and when we did so it did help the speed too. The only problem then is it is still riddled with bugs…of course, so is version 4.0.3. I think there were reports of it being faster than what you listed. I do know 4.1.2 fixed a bug with Google Chrome.
The other thing that was slowing down our site was we were not using the users browsers cache. Once I made some type of change on that it made a difference. The sad part is I can't remember what the heck I did to turn that on or make it happen. Unless you've already changed it CS-Cart does not seem to have this turned on out of the box. Hopefully someone else can tune in here and tell how to make CS-Cart use the users browser cache.
I did this in v2.24, obviously, but I cannot seem to find out how to do it in v4.03 . I did disable the categories all together and saw a huge improvement in speed. I just need to figure out how to limit the category view in v4.03.