Intel Xeon E5 2643 's Advantages
Higher base frequency (3.3GHz vs 3.2GHz)
Larger L3 cache size (10MB vs 8MB)
Xeon E 2104G 's Advantages
Released 6 years and 4 months late
Higher specification of memory (DDR4-2666 vs DDR3)
More modern manufacturing process (14nm vs 32nm)
Lower TDP (65W vs 130W)