PaleMoon to upgrade x64 minimum system requirements later this year.

 
We are doing this to get back to one of the core principles of Pale Moon: to provide an optimized, efficient alternative browser. 

For 64-bit on x86 hardware, we will move from a minimum requirement of a CPU with SSE2 support, to one that supports at least the AVX instruction set. In Intel terms, this means x86_64 v2 + AVX.
Any desktop Intel CPU released after approximately 2011 (Intel Sandy Bridge or later), and any desktop AMD CPU released after approximately 2013 (AMD Bulldozer or later) should support AVX.

Note:   Requirements for 32-bit Windows will remain unchanged.

Planned system requirements changes this year - Pale Moon forum

[ Hat tip to Corrine Chorney, for calling this to my attention. ]