AMD Radeon R9 M385 's Advantages
More VRAM (4GB vs 2GB)
384 additional rendering cores
AMD Radeon RX 540 Mobile 's Advantages
Released 2 years and 6 months late
Boost Clock has increased by 22% (1219MHz vs 1000MHz)
Larger VRAM bandwidth (96.00GB/s vs 76.80GB/s)