The new Mali-G78 mobile GPU is more efficient and provides performance improvements of up to 25 percent compared to its predecessor — Mali-G77, which launched last year as the first Valhall-based mobile GPU. Its companion, the Mali-G68, inherits features such as the new FMA unit, but only supports up to 6 cores (24 for the G78).
https://www.notebookcheck.net/ARM-unveils-the-Mali-G78-and-Mali-G68-mobile-GPUs.466886.0.html