EDIT: After examining my PC some I think I need to allocate more RAM to Caveman2Cosmos, but I'm not sure how much exactly. My DXDIAG tells me I have a little more then 3GB RAM available, will that be enough?
depends if you have XP or Win7/64
As Civ4 is a XP program it cannot address above 2.96 GB, if you use the XP 3GB switch.
Also the workable Grafic memory is limited to 2GB
If you have a grafic system that does use shared memory you need overall 4GB RAM
If you use a 64bit system, you don't neet the switch, as Win manages it, but the limit of 2.97 GB is nevertheless.
Sample: I habe Win7/64 with 16GB RAM and 4GB dedictaed VRam on Grafic board.
When I start Win, the system uses ~1.9 GB, after load C2C (main screen, before load a sav file), system uses 2.1 GB Ram, and after the sav of my current game is load the system uses 3.9 GB. The memory allocation failure comes, if the memory in use comes to ~ 4.8GB
Different ist is, if I open the world builder. Then it gets the memory allocation error before that border, as it does not empty the grafic ram well.
Also, a
grafic memory allocation error may be before the 3GB border, if the grafic settings of C2C are too high (animations, etc.) and to much stored in grafic memory w/o empty it correctly. This is a Civ4 bug.
Doing a sav each turn, exit and restart game may help in such cases.
Overall, the C2C v35 seems to work correctly (but the critical points I not yet reached in my game, so it is not yet a final word. I'm currently at "half automatic weapons". Magnet railroad and later will give a boost in vram usage, and when the world terraforming comes.
As good I noticed, that the AI factions do grow a lot slower and don't have hundrets of units in their cities as before where I had AI cites with more than 150 units in it.
Edit:
if there is a CTD the question also is, what is if you go one or two turns back and make some different.
Some CTDs seem to be cause just only if special things come together in same turn. I remember, in ROM I had a CTD just when a special great wonder and a special research meet together. I stopped the research for one turn, it comes no CTD and the game continued fine.
Edit 2
Bug or feature ?
see attached image. Ethanol Company is the only for that I habe in building screen the option to build it. All other Companies I can send out their managers and get the cites listed in companies, but cannot build it. Establish works fine, but w/o to build it. Except the Ethanol.
Edit 3
Paddle Steamer upgrade bug (?)
I have 3 Paddle Steamers only which I can upgrade to Transport, but all other Paddle Steamers I can't upgrade. Also I cannot build a Transport but Paddle Steamers only.
--
one turn later I can upgrade all Paddle Steamers and also build new Transporters
Edit 4
Command Bunker - Fort what minimum distance between and what new requirements?
Before I could set forts and bunkers, both minimum distance 2 empty fields between, while a bunker could be set direct beside a fort and reversed.
So BFxBFxBF was possible
Now I no longer can set forts when I can build bunkers, but the minimum distance also is changed? I have two bunkers with 4 free fields to next bunker or city and one with 5 free fields, but cannot build another bunker or fort.
It is confusing as by this I can't plan a "Maginot Line" well.
What are exact the requirements now or is this a bug?
Edit 5
this is a bug: get window that two cities of an AI faction had revolution and if they can come back or not. If not, then they will create a new faction.
I say NO, but nothing happens. The cities get back to the former AI, same as if I say YES