Dirty or Damaged Discs
Game and Blu-ray movie discs are subject to dirt, dust and finger print accumulation when not handled or stored properly in their associated casings. Users subject such recordings to damage when they cause the discs' sensitive surfaces to come in contact with hard or sharp objects. The PlayStation 3's optical reading component cannot properly decipher the data stored on discs coated with foreign particles or having scratches. Try alternate discs to determine if dust or scratches are the issue and carefully clean dirty discs with a soft cloth.
Improper Ventilation
The PS3's internal components build up heat during continued use. When operating properly, the entertainment console uses a variety of fans inside the system's casing to push hot air out of its vents. If they are blocked by external surfaces, such as carpeting, they cannot allow the heated air to escape. High temperatures build up inside the PS3's console and cause internal components to malfunction or the entire system to shut down. Reposition your PlayStation as necessary so all vents are exposed to the open air.
Poor Internet Connection
The PlayStation 3 requires an Internet connection to carry out certain tasks such as browsing the web and downloading files. The PS3 routinely "searches" for a valid Internet connection during operation to maintain applications. A poor or unavailable Internet connection inhibits the system's normal operation speed, causing freezing or a general lag during game play. Try alternate wireless routers or a hard wired Ethernet cable connection. Users can also turn off the PS3's Internet connection using the Network Settings Menu.
Hard Drive Issues
All PS3 models use SATA Hard Disk Drives to store data such as game files, movie files or whatever sort of information the user chooses to save on the system. PlayStation 3 hard drive sizes range from 20, 60 or up to 360 gigabytes of storage space. Faulty hard drives or those filled to their maximum capacity cause lags when accessing data. Remove unnecessary files from your PS3's hard drive or replace it with a larger, properly functioning drive.