It may be due to number of reason. First, if you are using mechanical hard disk (HDD), After using for few year, your data becomes more spread out. It means that the mechanical hard disk’s read/write heads will have to move more to gather the same amount of data and slow down the speed.

Secondly, it may be due to lack of memory(Ram). For newly application or software update, the application may use more memory, it caused your memory used up very quickly. After memory is not enough, it will switch the job to disk drive, if you are using mechanical hard disk (HDD), the performance will be significantly decreased, since it increased much read/write time on HDD.

Thirdly, if you are using 3D application or 3D graphic, newly 3D may require higher GPU graphic card in order to support higher 3D calculation. Otherwise, the 3D drawing will take longer time to render.

For first two problem, it may be solved by change the hard disk to SSD. For the last problem, it may be improved by replace a newer graphic card.