A lot of “experts” are saying that Cortex A15 are much faster than Cortex A7. The so-called “experts” are also tending to claim that even a quad core Cortex A15 is faster than Octa-Core Cortex A7. This is definitely far from being true.
So let’s try to figure out what’s really matter:
We have 2 Quad Core Cortex A7 SoCs:
MediaTeK’s MTK6589t 1.5Ghz Quad Core With PowerVR SgX544MP (Single-Core) GPU
AllWinnerTech A31 Quad Core 1Ghz with PowerVR Sgx544MP2 (Octa-Core) GPU.
Even though the MTK6589t suppose to be faster, If we will compare a MTK6589t device with 1920*1080 resolution with a A31 device with 2048*1536 resolution, We will find out that heavy games like Asphalt 7, Asphalt 8, NFS Most Wanted, Real Racing 3 are working flawlessly on 2048*1536 A31 device while lagging on 1920*1080 MTK6589t device despite the 50% increase in the CPU Clock’s speed comparing to A31.
It would not help in case MTK6589t would have A15 instead of A7. A31 would still be faster.
As you most probably have already guessed, The much faster GPU is the thing that actually made the difference in the case of A31.
One more example: MTK6577 & Rockchip RK3066 are both Dual Core Cortex A9 40nm SoCs.
Though MTK6577 with a resolution of 960*540 receive around 6500 AnTuTu score while a RK3066 with 1280*800 around 11000. This is because MTK6577 has a single-core PowerVR Sgx531MP while RK3066 has a quad core Mali400MP4. The GPU made all the difference once again.
Quad Core Cortex A7 is well capable of running all the heavy newest games and multitasking applications without any problems on high resolution even when connected to a TV screen through Miracast/HDMI when it has a strong enough GPU. The coming True Octa-Core Cortex A7 from MediaTeK will reportedly have a muti-core GPU which would significantly increase the performance under the high resolution screens.
The “Octa-Core” currently being available by certain CPU makers that combine the 4 Cortex A7 & 4 Cortex A15 cores are not so useful because most of them are technically quad core since they are unable to use more than 4 cores at the same time. Moreover, They are not even able to activate let’s say 2 Cortex A7 & 2 Cortex A15 Cores at the same time. They may only activate either Cortex A7 or Cortex A15.
MediaTeK has released a quad core SoC with 2 Cortex A7 & 2 Cortex A15 which is able to activate all the 4 cores at the same time which makes much more sense than the solutions presented by the other companies. MediaTeK is planning to release 6-8 cores mixed solution with also the ability to activate all the cores at the same time when needed instead of just the 4 cores. Moreover, They are the first to use the PowerVR SGX6 Series GPU which significantly increase the performance.