No it isn’t, because unlike Aero, the basic theme is not hardware accelerated. Aero runs just fine on pretty much any recent graphics hardware (yes, even integrated graphics); there’s really never any reason to disable desktop composition (except perhaps for troubleshooting purposes).

Does Windows Classic theme run faster?

Yes, obviously Classic Windows will be faster simply because there are less calculations to do. That’s also why it depends on the system. On fast systems, the performance improvement will be much less than on slower ones. … I personally always use Classic Windows, even in Windows 7.

Does Windows Theme affect performance?

While the load of themes in Windows 10 is negligible, it really depends upon the number of resources in your computer. … But if you have adequate hardware resources, the Windows themes have negligible effect on computer performance and will not slow down your computer at all.