Sometimes new users do not understand what they can and cannot do with Algodoo. For example, new users will sometimes try to generate large amounts of Algodoo water, and their computer will lag very badly or even lock up. Or they might generate huge numbers of circles or boxes, and that will do the same thing. When Algodoo cannot run a scene because it runs out of memory, it will often close and not save the bad scene. It will sometimes load the previous "good" scene rather than the bad one. That's why it will sometimes not save your scene and will open one that worked before. Algodoo is SMART!
So, the best advice that I could give you is, DO NOT MAKE VERY LARGE SCENES!
I have a 2gb ram laptop and i can still use algodoo just fine, even on some larger scenes. I would STILL reccomend upgrading RAM. Maybe there is a way to allocate more of your memory towards algodoo to use for itself..?
Phun is an OLD program, which means that you will only be able to run some of the older scenes that were created with Phun. A Phun user will not be able to run most of the newer scenes that were made with the newest versions of Algodoo. If that is acceptable, then maybe Phun would be a good alternative for some people.
@SecondLogic - I also recommend to upgrade your graphic card. But im not sure if the graphic card itself is causing the problem because my brother said that the graphic card of my computer is not placed (or maybe outdated) but i can still play Algodoo. While on my another computer with no graphic card, (it was burned ) I cannot play algodoo, it just crashes. but Phun works on my 2nd computer
Also, sorry if i separated my 2 comments or if this is long
Nah, the ONLY thing you can do to improve performance in Algodoo is upgrading your processor, but you have to buy an Intel. AMD processors are good for everything else but Algodoo (they have like half the performance of a comparable intel).
You won't note any changes if you change your videocard or RAM. believe me, Algodoo only uses a lot of CPU and a tiny bit of GPU, and 1500 mb of RAM (speed doesn't matter)
I know whats the problem
If you have a big scene and it causes alot of lag it might say something at the topright corner or if your scene is large but not to large to cause lag it will do the same but if you give it time you could probably save it and restart
Algodoo
I once was making a marble machine named Marble Machine Glass then halfway through build something popped up and said something in the topright corner
but thankfully I was able to save it and finish it and its in algobox so go to my profile.