On My Minecraft I'm Lagging Alot More Since The Horse Update
What I expected to happen was...:
To Just Play It Like Normal Not That Much Lag...
What actually happened was...:
When I Tryed To Move Or Jump/Sprint It Kept Freezing Until I Let Go
Steps to Reproduce:
1. Try To Sprint
2. Go In The Same Direction For A Few Secounds
3. Try Jumping
First try to update your graphic drivers from the manufacturer site
Second set system high performance
1. Click Start | Control Panel.
2. Click System and Security | Power Options.
3. Expand Hide additional plans category, select High Performance.
4. Close the dialog.
Optimize Background services
Click Start | All Programs | Accessories | Run.
Type SERVICES.MSC in the Open box.
Press ENTER.
Disable services that you don’t require.
I have found a presentation tutorial that will resolve your problem You are only required to follow the steps mentioned in the tutorial
http://www.slideshare.net/CarmenPomes/minecraft-15-lag-fix
Hopefully it will help you