The MK6592 is an 8 core device. The AnTuTu test is detecting only 6 active cores. This can simply be becauase the core management is allocating only six cores to the test and keeping the other two for the system - there will definitely be system services running simultaneously.
This is offered only as a possible solution - for a definitive answer you would need to find out how core management / multi-tasking is implemented at chip level and in the Android core.

It is so improbability
Because there have not 6 core phone on the market,
maybe the phone you buy is a retread phone

You can think about visit the professional store to know about the original phone

It's funny that it also reports the frequency at almost 1.5GHz. The MTK6592 is supposed to go up to 2.0GHz

This?

Attachment 54438

from:Comparative Review: Mijue M10, first under-USD150 8-core Smartphone Vs. Cubot X6 - xda-developers

Yeah, that's strange that Antutu and GFX report it as 6. The MTK6591 is supposed to be the hexa core where the MTK6592 is the octa core. Maybe there is something funny in the phone that is reporting the numbers incorrectly (either the chip or the number of cores incorrectly).

That's what I thought at first.
But I just saw a review online (XDA) about this Mijue M10, and I just saw the test result of Antutu...and you guess what, it's 6 core.
So I'm even more confused..
Sorry that I couldn't post any link..

Maybe it's a typo? The MTK6592 is definitely 8 cores.

Hello, guys. Bruno here and need some help.
I just ordered a so called 8-core cellphone from Tinydeal, it was cheap, less than US$ 150.
But then, I felt something incomprehensible.
As the title declares, it was 8-core, but in the description, they say it is Hexa-core with MTK6592 chipset.
But is that right? 6-core with MTK6592? I thought MTK6592 is just for 8-core cellphones. Besides, is there any 6-core cellphone available in the market?