Which one of these 2 CPU & GPU's is better/stronger?

Nvidia. The MTK set of chips are cheaper ones with lower clock speeds for the GPU.

 

MTK 6589 has a slower CPU for sure, but it's the Cortex A7 which is designed to be more power efficient than the Cortex A9 in Tegra 3.

I'm not sure about the GPU performance, based on GLBenchmark 2.5 results MTK 6589 GPU (SGX544MP1) is a little faster, in reality they're probably about the same.

CPU performance would let the Acer E2 overall, I guess it depends if you want battery life or CPU performance.

 

don't know much about cpu speeds quite frankly, but i have both.
nvidia on a transformer prime and the mt6589 on an android mini pc.

the mt6589 clocks 15034 on antutu. don't know the score on the transformer.

and the mt seems way faster to me in usage, but i suppose that could be because it has 2gb of RAM.

edit: never mind. realized the cpu on the android mini pc is a rockchip, not mtk. sorry for my babbling. i'm expecting a mtk6589 cellphone in the mail any day now. if i remember, i'll run antutu on both devices and report back.

 

In terms of the CPU, here's where they stand.

The Tegra 3 utilizes a quad-core Cortex A9 setup. Cortex A9 delivers 2.5 DMIPS/clock in raw performance (which can be hindered by slow ram, limited cache, etc.). At 1.5ghz, that is 3,750 DMIPS/core for a max theoretical of 15,000.

The MediaTek MTK 6589 utilizes a quad-core Cortex A7 setup. This delivers 1.9 DMIPS/clock. At 1.2ghz, that comes out to 2,280 DMIPS/core, or 9,120 theoretical max.

That means that the Tegra 3 has a CPU that is up to 65% (rounded up) faster than the MTK 6589. However, the MTK has much better power consumption. Which is more important to you, performance or power usage? (Tegra 3 uses a companion core, but its power savings isn't huge). The MTK is literally the lower-powered quad-core found in the Exynos 5 Octa.

As for the GPUs, I'm not an expert there, so I can only point you to the 3D Mark reference page (which is one of the more accurate GPU related benchmarks on Android right now).

Best Mobile Devices July - 2013

The top scoring Tegra 3 device scored a 3,204.
The top scoring PowerVR SGX544 (non-OCed, paired with a 1.2ghz quad A7) scored a 3,154.

What does this mean? In gaming situations, I would expect both devices to perform similarly. In CPU-related tasks, the Tegra 3 will be up to 65% faster. All around, the MediaTek will offer better battery life.

Ask yourself, which phone offers the best software for your needs? Possibility of official updates? Custom ROMs, if that's your thing?