AMD Radeon R7 M275DX vs NVIDIA GeForce MX450

AMD Radeon R7 M275DX

The AMD Radeon R7 M275DX is a Hybrid Crossfire combination of the integrated Kaveri Radeon R7 and a dedicated Radeon R7 M260, M260X, M265, or M265X (called Dual Graphics - DX). Both graphics cards use the AFR mode (alternate frame rendering) to each render a frame. Around 30 fps this Dual Graphics combination may suffer from micro stuttering due to different frame latencies.

The performance depends on the driver support for the used game. In some cases the game engine will only use the dedicated graphics card and therefore the M275DX may not be faster than e.g. a M260 alone. The other end of the spectrum are performance gains of up to 61% in our tests (Alien Isolation Benchmark with high detail settings). This was measured with an ideal combination of a FX-7600P and a M260 with dual channel main memory configuration. On average we measured a 13% increase compared to disabled Dual Graphics when testing 25 games. Looking only at the games that gain from Dual Graphics, the M275DX was able to gain 34% (see diagram below). However, there are some games where Dual Graphics is even slower than with disabled settings, so the user might need to test the settings out. With some games and enabled dual graphics we also experienced problems (e.g., stuttering and flickering main menus in F1 2014 and Shadow of Mordor, wrong texture settings in Ryse, hanging game in Thief, graphical problems with Fifa 15 and Dragon Age: Inquisition).

The shaders of both GPUs can be used for OpenCL calculations and therefore make use of both GPUs.

Furthermore, the M275DX supports Mantle (only light gains in some scenarios in our tests), Eyefinity and Enduro to in battery mode (use of the integrated GPU alone).

The maximum power consumption can be quite high using Dual-Graphics as both GPUs of the APU and the dedicated graphics card are running.

NVIDIA GeForce MX450

The Nvidia GeForce MX450 (N18S-G5, N18S-G5-B, N18S-LP codename) is a dedicated entry-level mobile graphics card for laptops. It uses the same TU117 chip as the GeForce GTX 1650 but with a reduced memory bus of 64 Bit. Furthermore, the MX450 is the first mobile GPU with PCIe Gen 4 x4 support. 

Currently four different versions are available with different specifications and performance:

N18S-G5-B: GBD-128 Package, 1395 - 1575 MHz, GDDR6 5001 MHz, 28.5 W
N18S-G5: GB2E-64 Package, 1395 - 1575 MHz, GDDR6 5001 MHz, 25 W
N18S-G5: GB2E-64 Package, 1395 - 1575 MHz, GDDR5 3501 MHz, 25 W
N18S-LP: GB2E-64 Package, 720 - 930 MHz, GDDR6 5001 MHz, 12 W

Especially the LP = Low Power variant is significantly slower than the typical 25 Watt variant.

The 25 Watt GDDR6 N18S-G5 should be up to 20% faster than a GeForce GTX 1050 but of course below a GTX 1650 (Max-Q). Therefore, demanding games like Horizon Zero Dawn should run lowest settings. Less demanding games like F1 2020 can be played in medium to high settings and full HD.

The TU117 chip is manufactured in 12nm at TSMC and thanks to the relatively low power consumption (TGP specified between 12 and 28.5 W) the dGPU is also suited for thin and light laptops. Mostly it is intended as an additional graphics card for Tiger Lake-U based laptops.