Your issue is very likely insufficient Power Supply wattage. Note that the total Wattage Rating of a Power Supply doesn't have much meaning in itself. Different computer systems have different Wattage requirements at different Voltage levels. Old Power Supplies had just basically just 5V and 12V power rails. Newer computers have added the need for 3.3V power rails and even smaller voltage rails. My three year old 650W BFG PS has seven separate power rails with 3.3V, 5V, -5V, 5VSB, -12V and two 12V. Each rail has its own power rating that must not be exceeded. The negative voltage rails can be ignored, since no add-on devices will use them for power and they typically have a low power rating anyway. The maximum power rating of each rail should appear on the power supply's case and on the box, if you bought a retail replacement like I did. My advice is to keep each rail below 60% of its maximum rating. That's very hard to compute or measure, so just add +50% to +100% (double) to whatever the box builder recommends.
Only one power rail needs to be close to its maximum power rating for unstable operation. (Just to be clear, stable operation means running a system continuously for at least several years without rebooting. That usually requires a UNIX or Linux operating system on server quality hardware as opposed to desktop/laptop quality hardware.) Unstable operation often means some failure while booting or shortly thereafter, but it also means intermittent errors that may occur as little as a few times a month or year.
It might be helpful to identify the power supply. The part of the PS case that is exposed near the back of the system where the PS fan should have the PS vendor and model stamped/printed on a metal plate or sticker. From that information, you can look up the Power Supply's power rail specifications on the PS vendor's site or a hardware review site.
It is a fact that the first place where system builders skimp on quality is the power supply, since extremely few people will insist on a server quality power supply in their desktop system. All the big box builders like Dell and most small box builders use third tier (mostly reliable at low power demands) power supplies in the systems that they build to keep costs low.
Power Supply Recommendations:
1) Use a Power Supply vendor with a great reputation for quality like PC Power and Cooling, Antec, or any vendor whose power supplies are consistently rated high at reputable hardware review sites.
2) Always get a Power Supply with a Wattage Rating of +50% to +100% (double) more than you are sure you need.
3) Try to ensure that peak power demands on each power rail doesn't exceed 60-70% of that specific power rail's maximum rating.
All computer issues that aren't 100% reproducible are probably due to a low quality power supply or a quality power supply with insufficient power on one or more rails.
Sun Tzu Wu
My computers have been suffering of similar problems over the last few months. I have browsed the Civ4 Technical Support sub-forum in search of advice, but
Sun Tzu Wu's posts here seem more enlightening to me.
I have been playing Civ4 since 2006 IIRC. In 2008 I bought a new PC with the specs below:
WinXP
Core2 6550 2.33GHz
MoBo Intel DG31PR
2GB RAM
Nvidia GeForce 8600GT Zogis
PS 450W Extream
HD160GB
Over the next 3 years I played and submitted countless games for GOTM and HOF, but starting this year it began to show screen corruption and game freezing that required rebooting, very similar to Misotu's report - same graphics board. Over the months, the issue became more frequent (but some months I was able to play several games with no problem at all), so I decided to buy a new PC, with the following specs:
Win7 Home Premium 64bit
AMD Phenom II X4 965
MoBo Gigabyte M68MT-S2P
4GB RAM
AMD Radeon HD6870 Xfx
PS 650W MaxPower
HD 1TB
I thought I would be safe, and indeed it worked ok for a couple of months, but then, while playing Civ4 (happened while playing vanilla, warlords or BTS) the screen simply would go blank. The case and monitor power leds were still on, but other than that I had to press the system's power button for several seconds for it to reboot.
I removed the new graphics board and sent it to test in the store, and played successfully a game with the old system's graphics card. However, while playing another game today, the corruption issue I suffered with the old system happened on the new one (which still had the old graphics card on).
The store tested the newer card and told me there were no issues with it.
I have all the game's versions updated, the sound and graphichs drivers also have the latest versions available. I have ran gpu-z and the GPU temperatures don't exceed 70ºC. Since this weird stuff started, I have been using my PC with its cover removed to help with cooling, but doesn't seem to have helped.
Next step is to take the newer rig to the store (with the new card installed) and see if they can reproduce the issue. But I would be very grateful if someone could offer me some advice.
p.s. If the mods prefer they can move this post to the tech support sub-forum.
