Virtual memory setting? 

It's part of the trouble shooting; the game takes a significantly large memory cache to run properly.

Not a tech guru, just posting from personal experience.  I'm running an I7 on a laptop with integrated graphics and 16GB ram.  I do fine with non-insane maps since I raised my virtual memory/ paging file to 20GB.

Quoting JMJimmy,

reply 3

I suppose the HDD could be an issue.  It doesn't really access the HDD very much when it's slowing down and 5400 is pretty standard for laptops...

Paging file was 2087MB used, 10485MB available

The thing I was seeing was when doing nothing - just letting it sit, no saving/no moving around/etc. the basic animations of the background/clouds/etc were enough to cause it to slow down.  It really seemed like a graphics or physx(?) issue

While typing this I decided to see what resources were being used up:



 

As you can see nothing is really straining but it was 1-10fps at best.  The highest I saw disc usage get (post loading the first 2.5gb) was 20% momentarily.

It's your graphics card and RAM. I had the same issues (to a lesser degree) because at the time I was running a GTX 560Ti card, but I had 16GB of RAM. and running Win 7.

Upgrading to a 750Ti helped, but I would still experience some big drops in framerate. You have to understand also that this was before the Devs began to streamline things.

I have since done a complete rebuild...i7-6700, 32GB DDR4 (2666) RAM, GTX 1060 6GB graphics card, Win 10.

It runs flawlessly now, even on insane maps with 50+ races.

Your computer is almost identical to mine, except I have Win7.  I don't have a problem playing GalCiv3 with mostly high settings - everything is very smooth.

You don't mention which GPU you are using.  GalCiv3 will use the default one, which might be the Intel HD 4000.  I know from experience that it is not as good as the 650M.  To determine what GPU is being used, do the following:

1. Right-click on the desktop.
2. Choose NVIDIA Control Panel.
3. On the left side, choose Manage 3D settings.
4. In the middle, choose the Program Settings tab.
5. Wait for it fill the list with programs on your computer.
6. Find Galactic Civilization III in the list and select it.
7. See what the preferred GPU is for it.
8. If it shows Integrated Graphics change it to the NVIDIA GPU.
9. Close the control panel.

This should allow you to play without a problem.

I also get this sometimes exactly as you described it.  I have had it since I installed GalCiv3, but I sometimes get it on other programs.  I have no idea what causes it.  It seems to be something related to the graphics driver.  I sometimes get a message that the graphics driver has recovered from an error.  My only suggestion is that you shut down your computer, restart it and hope for the best.

Two very important pieces of the picture you do not mention is how many opponents you are playing with in how large a galaxy. With only 8G RAM you will not be able to play with the maximum number opponents on the larger galaxy sizes. Your OS's virtual memory setting can also be a factor.

Well I think the suggestion for less than 16-32 gigs of memory is to avoid the excessive, and insane maps. One suggestion is to run Ccleaner on a regular basis. You could gear windows for best performance. Remember that if galactic civilizations is shrunk to the task bar I heard that it is not really being used, so the resurce monitor while you are typing is not really effective. Make sure your power settings is set for high performance, not balanced, or the default power plan of some manufacturers that all non tinkered computers is set to by default. Go to the galactic options on the game, and set the options to low performance. Also the other advice sounds good.