A computer has a CPU as well as memory. Storage (Hard Disk, SSD); There is also a graphics card (GPU) and other components. You also need to consider the software (for example, antivirus software) that runs on the operating system (Windows / Mac / Linus).
If you run different versions of Windows (eg Windows 10 and Windows 7) on the same computer, the speed will be different. Antivirus installed and not installed are not the same speed. The reader should realize that just by using the Core i7, the tortoise does not immediately become a rocket. Other components must be compatible with the Core i7 to get the full speed. (Suppose one worker bakes bread and the other packs the bread. If one worker is replaced by someone three times faster, he or she will get three times as much bread, depending on the other person, right?)