Sometimes it happens, when you play an old game which is compatible with new OSes that some issues occur. Such as huge increase of speed. In that case the game is totally unplayable.
This happens because although the specific game is compatible with new OSes, (for example a Windows95 game which runs in Windows 7) , it's not compatible with new hardware because the game was designed and programmed to run in slow systems, which where common by the release date, so that new fast CPUs and GPUs affect the solid game performance.
In the following links you can find several "slowdown utilities" which will decrease the speed of your modern CPU while playing the "speed-affected game". The speed is decreased only while the utility is running, which means that when it stops running, then the CPU speed comes to its normal standards.
Some of them are freeware, others are commercial. Some of them are simple, others are more complicated. But not a big deal. Also some of them such as "turbo",which is the simplest one, need to be used in compatibility mode (Windows Xp and lower), but since they are very simple apps, there shouldn't be any issue.
http://www.sierrahelp.com/Utilities/SlowdownUtilities.html
http://vogons.zetafleet.com/viewtopic.php?t=8070
http://www.oldskool.org/guides/oldonnew/resources
Games that have such speed issues are: Zork Grand Inquisitor, Cladestiny, the 11th Hour, Black Dahlia. And definetly some more. these are the ones that I played and had this behavior.
Note: If a game which runs with DOSBox has this behavior (for Example Dark Half of Capstone,1993), then the issue can be resolved via the DOSBox settins (CPU type, Core Cycles).