Bug: Win 7 x64 compatibility mode makes program run on only one core

[Seraiel]

Hi...

I have a problem when trying to run a certain program in compatibiility mode. Whichever compatibility mode I use (tested Win XP SP2+3 and Win 7 compatibility mode) , it makes the program only use 1 of 8 cores (4 with HT) . When I run the program normally, so without compatibility mode, it uses all cores, but then the process remains in the task-explorer forcing me to manually remove it, if I want to re-start the program without rebooting.
I've googled compatibility mode Windows 7 and program only using one core but didn't find anything, which is why I ask for help.

Seraiel

 

[Mellon Head]

Is this an older program? I'm confused why it would run properly on all cores but be stuck in the task manager like that. Which program is it?

 

[Seraiel]

The program is Civilization 4 - Beyond the Sword. That game is many years old, but it's still the (imo.) best game of the whole TBS-genre.

 

[Anak]

This is one approach for Fallout3 to run, but it may be of some help, see if the steps look familiar especially:

• #6, the affinity setting

• #7, I'd still check the settings for users, C4-BtS was designed for more than one core.

• And #8's suggestions.

https://Getting Fallout 3 to run on Windows 7 - 64 Bit | steamcommunity.com


Here's a reddit discussion: How Civilization V was built for multi-core processors

 

[Mellon Head]

• #7, I'd still check the settings for users, C4-BtS was designed for more than one core.

Actually, Civ4-BTS is single threaded, however, using a multicore machine allows Windows to use more cores for housekeeping, freeing up the Civ4 core for the game. I've done extensive testing for my mod and found this to be the case. Civ4 will only use one core.

The program is Civilization 4 - Beyond the Sword. That game is many years old, but it's still the (imo.) best game of the whole TBS-genre.

You're right, it is the best TBS game ever.

I'm curious why your game would stay in the task manager and that you have to end it manually. I never have this problem. My computer lets go of Civ as soon as I end it.

I know that you play a lot of HOF games, I wonder if it could be something with BUFFY? Or does this happen in standard BTS?

 

[Anak]

Thanks for the clarification MH.

 

[Seraiel]

This is one approach for Fallout3 to run, but it may be of some help, see if the steps look familiar especially:

• #6, the affinity setting

• #7, I'd still check the settings for users, C4-BtS was designed for more than one core.

• And #8's suggestions.

https://Getting Fallout 3 to run on Windows 7 - 64 Bit | steamcommunity.com


Here's a reddit discussion: How Civilization V was built for multi-core processors

Thx, but I cannot change anything about the game process, because I play competetively and need to use a mod, that disallows any alteration towards the game.

• #7, I'd still check the settings for users, C4-BtS was designed for more than one core.

Actually, Civ4-BTS is single threaded, however, using a multicore machine allows Windows to use more cores for housekeeping, freeing up the Civ4 core for the game. I've done extensive testing for my mod and found this to be the case. Civ4 will only use one core.

The program is Civilization 4 - Beyond the Sword. That game is many years old, but it's still the (imo.) best game of the whole TBS-genre.

You're right, it is the best TBS game ever.

I'm curious why your game would stay in the task manager and that you have to end it manually. I never have this problem. My computer lets go of Civ as soon as I end it.

I know that you play a lot of HOF games, I wonder if it could be something with BUFFY? Or does this happen in standard BTS?

I also thought it would be single threaded, but when I run CIV normally, so Win 7 x64, no compatibility mode, all cores are used at about the same %. When I use compatibility mode, 7 cores are quiet and one is at 100%. To me, this actually doesn't look, like it were really single threaded. I know, the game is very old, but maybe Win 7 x64 and higher simply have sort of a trick to divert the handles of a game towards multiple cores.

And interestingly, the problem with the process not getting removed out of the task-manager isn't a 100% bug anymore. It was at first, but the last 3 times I exited CIV, it properly shut down.

Btw.: Nice to see other players from CFC being active here aswell .

 

[LMiller7]

I am guessing that setting the compatibility mode either directly or indirectly is setting CPU affinity to 1 core. Many of the details of what the compatibility modes do are not officially documented. When XP was released there were no multi core CPUs for the PC market and multiple CPUs were generally limited to servers and high end workstations. Some applications of that era, and newer as well, have issues on multi core systems. Restricting affinity is not an unreasonable thing to do in such cases. Windows makes accommodations for applications with known issues and that may play a part as well.

I know this is a lot of guessing but many of of this is undocumented and that is all we have.

 

[Mellon Head]

I also thought it would be single threaded, but when I run CIV normally, so Win 7 x64, no compatibility mode, all cores are used at about the same %. When I use compatibility mode, 7 cores are quiet and one is at 100%. To me, this actually doesn't look, like it were really single threaded. I know, the game is very old, but maybe Win 7 x64 and higher simply have sort of a trick to divert the handles of a game towards multiple cores.

Ok. I did some testing with BAT 5.0 (not released yet). As you know, BAT has almost the same CvGameCore.DLL as BUFFY, but it's more memory intensive. That's why I used it.

Anyway, I found that with my 8 core CPU, one core really jumps up (to about 70%) when in run BTS in normal mode, and goes to zero when I ALT-TAB out of the game. The other cores behave normally, and seem to run independently of the single core which shows activity with BTS. One thing... a second core shows significantly increased activity once the game begins to run, that is after the save is loaded. I used a large save, from 2008 game time, and there are lots of units in play. I don't think this core is running the game, but is picking up the normal processes from the PC that are no longer being used on the core that is running BTS.

On the other hand... you may be right. Win 7 x64 might be dividing the workload among cores. That second core dramatically drops in activity when ALT-Tabbing out of the game. Then again, it could be this stupid CPU of mine not being a real 8 core, and the virtual core might be shadowing the real core. Note that I only have two cores with really significant activity, the others are idling during play. I'm not convinced that Civ4 is actually multithreaded.

Note that I can't get BTS to run in compatibility mode. It fails on start up.

Btw.: Nice to see other players from CFC being active here aswell .

Of course it is. Quality people are everywhere.