Just wanted to say that now the game is running fine (3570k@4.1GHz GTx570 windows8 64bit). I don't know exactly the reason. I am still running it mute in compatibility mode with windows 95. I closed a few programs on the background as suggested. When I chose to play the campaign I noticed the game was not having lag issues anymore. At the moment I am playing a single player match and things are going well. First time I launched the game instead it was really very slow with a lot of lag, but now I am happy the game is working fine, and I am really enjoying it. I hope everyone will be able to solve the lag problem, the game is really worth. I rated it 5 stars, very nice game really :) Even if to be perfectly honest a patch to solve these issues would be the best thing, so when people buy the game they won't have to struggle to try to run it fine (since it seems the lag problem seems to be common).
Regarding the cpu usage, windows 8 task manager says Eador's cpu utilization is 30%, and my cpu temperature stays between 30 and 40 degrees while running the game. Using BES or running a second instance of the game didn't helped me with the lag problem. At the beginning I turned off the music and I ran the game in compatibility with win95. That helped reducing the lag, but the game was still very slow. Maybe closing other programs helped ( just had core temp and the browser opened), or I don't know for what reason after I tried to run it multiple times it finally ran well. I have no idea why, but now the game seems to work well now. I tried a few times and no problems at the moment.

Hmm wonder what the deal is, I also have a 2500k,GTX670,Win7 64bit and no problems at all. Sometimes I switch back to a browser flash game works well,too. Comodo is running,but nothing else, not using steam.
I set the switch on in the shortcut compatibility settings at deactivate visual designs and desktop,but I do that with all games.

Running two instances of the games seems to clear up almost all of the lag issues.

I found that opening two instances, closing the second and going back to the original instance also seems to keep the lag at a minimum.

Go figure. I just wonder why this solve most of the lag problem unless by having more instances allots more memory to Eador.

Update on my machine:

I'm running an i5-3570K CPU with 8 GB and a GTX 670. With High Performance power profile running under Windows 7, and Chrome (4 tabs) and Steam running, I get all of the issues: laggy mouse, sound crackling (especially when I move the mouse pointer left and right causing the direction of the scrolling landscape in the main menu to change direction), etc.

When I close one of those apps, it's noticeably better, but there's still some lag and sound crackling.

But when I close both so that only the game's running (as shown on the taskbar), performance is flawless. It's very bizarre, but the game doesn't like other apps running (I don't have to close any of the processes running in the background, such as McAfee, Dropbox, etc.).

EDIT: There's still some minor sound stuttering every now and then while playing the game, but the mouse is no longer laggy.

Having jumped through various hoops described in this thread, I finally decided to try the windowed mode just for the heck of it. Much to my surprise, it reduced the lag to a tolerable level. At least I can now play the game, though it's not the optimal solution.

Eador is indeed a very good game. A patch that fixes the lag problems would be more than welcome, but I'm not holding my breath.

This issue is related to timers' code in the currently deprecated version of Allegro Library used for creating Eador: The Genesis. This functionality is not well-suited for 3000Mhz+ CPUs and/or dynamic frequency control (all kinds of power-saving mechanics). The only way to get rid of this is to port the game on the new version of Allegro. Several attempts were made by the author (Adrageron), but its complicated by the need of porting some abandoned third-party snippets used in the game (also based on the deprecated allegro version).
Original post on Eador.com forums (Russian) [Google translate (Lame)]

So far, the only possibility to patch it is outsourcing to some Allegro-expirienced programmer.

PS: Expirienced users can utilize virtual machines to run Eador, it seems to work well in this environment regardless of CPU specs.

Maybe disabling some C-states in the bios could help, if its an issue with power saving?

I have a slower Core I5 with Windows 7 64 bit, and a Logitech mouse, and it was pretty miserable. I did as everyone suggested and turned off the sound/music, but it wasn't an improvement. The most improvement I got was by placing the Eador.exe as an exception in my antivirus software, but the mouse was still jumpy or would slow down.

I don't know if this will help anyone else, but I noticed that in my case the mouse would by smooth and fine over everywhere but the menu button areas. I thought it might be my mouse driver so I created a different profile and changed some dpi settings but it didn't make any difference. I then noticed that under a section for "Pointer Movement Settings" the default had the "Use OS native drivers for pointer speed and acceleration" checked. I unchecked this and suddenly the game no longer had mouse jumps.

I actually could have some programs in the background and it didn't affect the game play (Winamp and Thunderbird). In my case, the game didn't like the Microsoft drivers for the pointer.

I have the same problem. This is too miserable. Kind of sorry I purchased this game as it is just not playable. win 7 64; 6950; 2500k processor. Bleh.

Was unbearable for me, but I solved the problem by setting windows 95 compatibility mode and 640x480 resolution from the compatibility menu.
It's alright now, even though chrome with tons of tabs and flash running in the background.

POSSIBLE SOLUTION for laggy mouse pointer (Windows 7):
Start -> Control Panel
Hardware and Sound
Mouse
Pointer Options Tab
Turn OFF "Enhance pointer precision"

I too had laggy mouse problems - moving the mouse slowly would not cause the pointer to move at all, and moving it quickly did not allow fine enough control to make the correct selections. I tried shutting down other applications, running in Win 95 compatibility mode, and running multiple instances as suggested by others in this thread but none of these fixed the mouse issue.

The quick fix above makes my mouse pointer as smooth as silk, hopefully it will work for others too!

Unchecking the enhanced mouse pointer helps a little bit more. Thanks for the advice

This is really a disappointment GOG. I hope you can figure something out, or offer refunds.
I am willing to close down Chrome, even so far as to close down Steam. But to close my Anti virus and whatever else? That is already too far just to play one game. No other game requires this of me. Rearranging my computer every time I want to play is not something I was told of before purchasing this.
I've rarely had any issues with you guys, this is looking to be something that will leave a negative mark. There is no excuse for this game to be running like this, and not mention this to customers.

Even after closing down Steam, and Chrome, the game was still stuttering and skipping about.
The right action here is to offer refunds. Now that would leave a very positive mark. Customer service and satisfaction.
I wanted this game, after all I paid for it, but not in this state.

Maybe I'm just a lucky possessor of a not-so-new notebook (Vista, 2x2.4GHz, 4GB RAM), but I don't have problems. Today I had some mouse lag, now it's ok. I have many programs in the background (Comodo Antivirus, Daemon Tools, SpeedFan, BES at 30% for Eador, sometimes Opera and Free Download Manager), and I don't see much difference.

I have also installed MS Visual C++ red. 2005-2008-2010 and .NET Framework 3.5, if this can make a difference.

This is my Eador.cfg

***MAIN SETTINGS***
Sound (0 - off/1 - on): 1
Windowed (0 - off/1 - on): 1
Run background (0 - off/1 - on): 1
Refresh delay (default 40): 20
Poll mouse delay (default 25): 5
Keyboard delay (default 500): 250
Keyboard repeat (default 500): 250
Sound buffer (default 20000): 40000
Color depth (16/24/32, default 32): 32
Sleep time (default 50): 25
Antiblink Delay (default 1): 0
YuPlay (0 - off/1 - on): 0
Intro (0 - off/1 - on): 1
Wallpaper (0 - off/1 - on): 1

***GAMEPLAY PARAMS***
Static loot (0 - off/1 - on): 0
Static event (0 - off/1 - on): 0
Resource price modifier (default 5): 5
Max percentage profit (default 500): 500
Mercenary change time (default 7): 7
Event possibility (default 30): 30
Max battle duration (default 40): 40

***ADDITIONAL SETTINGS***
Max illustration (default 107): 107
Max path (default 20): 20
Lake ships (0 - off/1 - on, default 0): 0