Those eight cores of the MT6592 don't mean something ultra powerful, though, as they are all lowly Cortex-A7 ones, that's why MediaTek has no worries about overheating, and the AnTuTu score around the 25 000 mark show that we can't expect much more performance from those compared to existing chips, but the octa-core tag on your phone's specs might compensate for that...
Source: http://www.phonearena.com/news/First-true-octa-core-mobile-processor-to-arrive-November-20th_id48717
Source: http://www.phonearena.com/news/First-true-octa-core-mobile-processor-to-arrive-November-20th_id48717