AMD Radeon RX 540 vs NVIDIA GeForce 945M

AMD Radeon RX 540

The AMD Radeon RX 540 is mobile mid-range graphics card for laptops based on the Polaris 12 chip (most likely). It is manufactured in an improved 14 nm FinFET process at Globalfoundries. The performance should be between the Radeon Pro 450 and 455 in the MacBook Pro 2016 range that is also based on the Polaris architecture. AMD specifies the RX 450 at 1.2 TFLOPS (Pro 450 1 TFLOP, Pro 455 1.3 TFLOPs). Compared to Nvidia graphics cards, the gaming performance should be between the GeForce GTX 950M and GTX 960M.

The features of the Radeon RX 540 are identical to the faster RX 460 and all other Polaris chips. See more details on the Polaris architecture here.

The power envelope of the faster Radeon Pro 460 is rated at 35 Watt according to the AMD blog post. Due to the slower specs, the Radeon RX 540 use slightly less.

NVIDIA GeForce 945M

The NVIDIA GeForce 945M is a mid-range, DirectX 12-compatible graphics card for laptops unveiled in March 2015. It is based on Nvidia's Maxwell architecture (GM107 chip) and manufactured in 28 nm. The 945M offers 512 shaders (compared to the 640 of the GTX 950M) clocked at 928 MHz. The dedicated DDR3 graphics memory is connected with a 128 Bit bus clocked at 1000 MHz (effective 2000, 32 GB/s). 

Architecture

Compared to Kepler, Maxwell has been optimized in several details to increase power efficiency. Smaller Streaming Multiprocessors (SMM) with only 128 ALUs (Kepler: 192) and an optimized scheduler should lead to better utilization of the shaders. Nvidia promises that a Maxwell SMM with 128 ALUs can offer 90 percent of the performance of a Kepler SMX with 192 ALUs. GM107 features 5 SMMs and thus 640 shader cores, 40 TMUs and 16 ROPs (128-bit interface).

Another optimization is the massively enlarged L2 cache (GM107: 2 MB). The increased size can handle some of the memory traffic to allow for a relatively narrow memory interface without significantly reducing the performance.

GM107 supports DirectX 12 with feature level 11_0 only.

Performance

The performance of the 945M is slightly worse than the GTX 950M but clearly faster than the 940M. The DDR3 variant of the GTX 950M is about 10 percent faster for example. Therefore, it is most suited for medium details of demanding games in 2015 (see below for benchmarks).

Features

GM107 integrates the sixth generation of the PureVideo HD video engine (VP6), offering a better decoding performance for H.264 and MPEG-2 videos. Of course, VP6 supports all features of previous generations (4K support, PIP, video encoding via NVENC API). Unfortunately, HDMI 2.0 is still not supported.

Power Consumption

The power consumption of the GeForce 945M should be somewhere around 40 Watt. Therefore it is most suited for bigger laptops from 14-inch and up.