*SOLUTION FOUND (FOR ME)*
Im including the entire story here, but for those who cant be bothered with meaningless rambling (which I tend to do), the general summary is that after trying all sorts of solutions (all the ones recommended in these forums, as well as others) I inadvertently fixed this problem on MY computer by installing Omega's nVidia drivers. Omega drivers are well-known, but for those unfamiliar with them, they're a third party provider that offers performance-tweaked, quality-improvement drivers for nVidia and ATI cards. People usually install them to improve texture quality for other, more memory-intensive games, but they're also known for stability. I installed them trying to improve Call of Duty 2, but I noticed that they fixed the crashing issues with my Civ Warlords game, even on Huge maps with graphic settings set to maximum.
www.omegadrivers.net
Basically, my background story is the same as everyone else's: I would receive a "Failed to allocate video memory. Please try reducing your graphics settings" message about halfway through single-player games on Standard maps or larger (usually in the early modern age on Small or Duel maps). I found this very annoying, but also very interesting, especially b/c the game ran just fine on my much older, much outdated desktop. My laptop (where I would receive the error) has 1GB RAM, a 256MB nVidia Geforce 7300 card, with Intel Duo Core processor(s) at 2GHz each. I had a hard time believing it really was my mediocre laptop's fault when I realized I could finish a full Huge-map game on my 4 year old desktop with half as much RAM and a 64MB Geforce MX440 card (admittedly it would run a little slow, but it NEVER crashed).
I tried so many solutions my head still hurts. I re-installed Windows XP, updated my BIOS, my chipset drivers, upgraded back to Service Pack 2 etc. etc. and re-installed Warlords. It still kept crashing. I enabled the HideOutOfRAMWarning option, and almost had a heart attack when it worked pefectly for a few more turns, then almost had a stroke when it crashed without warning. I tried the Memory Saver option. I tried disabling PAK memory mapping. I lowered my graphics all the way. All delayed but none actually fixed the inevitable crash.
I eventually gave up, hoping (I still do) that Beyond the Sword would correct this issue. Then months later, while looking for a way to improve texture quality for Call of Duty2, I decided to install Omega's Drivers (which Id known about for some time, but never actually tried). I replaced my nVidia drivers with their nVidia forceware 1.6693 version. Call of Duty looked even prettier.
And then one day my friend asked me to fix resources and starting locations for this Earth scenario of his, on Warlords. I opened it, went to worldbuilder, and got to work. It took me about 20 seconds to realize...my game was running smoothly. Like, very smoothly. I panned around, I sporadically clicked on the mini map, I zoomed in and out and in again- it was borderline magical, IT DIDNT CRASH. Determined to prove myself wrong, I upped all the graphic settings to maximum and went to 1680x1050 resolution (highest allowed on my monitor), then opened an old save file (Huge map, 18 civs, hundreds of cities/units all over the place). I actually finished the game, and was so happy I started a thermonuclear war instead of trying and finishing with a high score. IT DID NOT CRASH; it didnt even do that choppy stuff it does when its about to freeze.
Im interested to hear if these drivers fix other people's issues as well. Its not like I made a great discovery or anything (Omega drivers have been around for A WHILE). But at least to ME it makes sense: my old desktop has older drivers, my newer laptop has newer drivers, and I've heard lots of people complain about certain instability issues on newer drivers putting too much load on a computer's video memory.
For those unfamiliar with what to do, here's my recommendation. PLEASE LET US KNOW if Omega drivers work for you too. I wanna know b/c this isnt a "core fix", its just a set of third party drivers, but they might fix the issue for other people as well.
1) Download the driver installation file at
www.omegadrivers.net
2) Uninstall your current drivers. Control Panel -> Add/Remove Program for Nvidia Drivers; Im assuming its the same for ATI.
3) Run the downloaded file; itll extract some stuff then run the installation.
4) It should restart, if not do this yourself. Upon reboot, the Found New Hardware menu should pop-up; you're updating Display Adapters. Choose "Install from specific location" -> Dont search. I will choose driver -> Have disk -> (Folder where files were extracted, usually C:\Program Files\Nvidia Omega Drivers for nVidia version, probably similar for ATI) -> Choose the nv4_disp.inf directly inside the 2KXP_INF folder -> (see Step's 5 and 6) install.
5) They're not digitally signed, just ignore these warnings. DONT REPLACE NEWER FILES; if it says theres a newer version of anything, dont replace it. (My computer didnt work the first time i tried, when I overwrote existing files, but when I later selected No to All it worked perfect).
6) If your particular card isnt on the list, you may have to do some research to find what category it falls under. I have a Geforce 7300 GO card, which wasnt listed, but I asked a friend and he told me this is also known as an Nvidia Quadro NVS 110M card, so I chose "Nvidia Quadro NVS" as my card, and it worked.
7) Restart when everything is installed.
8) I still have the "HideOutofRAMWarning" set to 1 in my civilization.ini file. I opened Rhye's and Fall of Civilization on maximum settings and when it finished "loading" it gave me the message, but instead of crashing it kept playing normally. (???) So I disabled the error notification feature and the game works fine. Strange.
I just quit playing CivIV, I can't get it working properly.
(the absolute only difference is that my X300 is 256 mb)
