Whenever I am playing a graphic intensive game, such as GTA IV, with my laptop plugged in to its AC power, it lags. However, the instant I remove the power cord from the laptop, the FPS triples and the game runs smoothly. I have already checked my power options and I have Performance mode on. I also checked the advanced settings and everything looked fine in there. How can I diagnose the cause of this problem?
P.S. Kaspersky isn't causing the problem because this problem was occurring before I installed it.
OS Version: Microsoft Windows 8.1, 64 bit
Processor: Intel® Core i7-3630QM CPU @ 2.40GHz, Intel64 Family 6 Model 58 Stepping 9
Processor Count: 8
RAM: 8084 Mb
Graphics Card: Intel® HD Graphics 4000, -1984 Mb
Hard Drives: C: Total - 953340 MB, Free - 213145 MB;
Motherboard: SAMSUNG ELECTRONICS CO., LTD., 350V5
Antivirus: Kaspersky Total Security, Updated and Enabled