AMD Radeon RX 7900 XTX vs NVIDIA GeForce RTX 3080 Laptop GPU

Performance

The Nvidia GeForce RTX 3080 Laptop GPU or 3080 Mobile (for laptops, GN20-E7) is the fastest graphics card for notebooks in early 2021. It is based on the GA104-775-A1 Ampere chip and offers 8 or 16 GB GDDR6 graphics memory with a 256 Bit memory bus. It supports PCIe 4.0 and will be available in different variants from 80 - 150 Watt (TGP) (80, 90, 115, 125, 135, 145 and 150+ Watt). As package the notebook graphic card uses GB5-256 and the chip size is 40x40mm. The GPU supports eDP 1.4b to connect the internal monitor.

There is no more Max-Q variant (formerly used for the low power variants) but every OEM can choose to implement Max-Q technologies (Dynamic Boost, Whispermode).

The performance depends on the TGP setting and cooling of the laptop. At the same TGP level the RTX3080 should be faster than the old top model, the RTX 2080 Super Mobile and similar to the desktop RTX 3070. This means, the GPU should be well suited for 4k gaming or QHD with high frame rates. The similar named RTX 3080 desktop card is significantly faster.

The GA104 chip offers 6,144 FP32 ALUs of which half can also execute INT32 instructions (i.e. 3,072 INT32 ALUs). With Turing all shaders could still execute FP32 or INT32 instructions. The raytracing and tensor cores on the chip were also improved according to Nvidia. The Ampere chips also include an improved 5th generation video encoder (NVENC for H.264 and H.265) and a 7th generation decoder (for various formats now including AV1).

The GA104 chip is manufactured by Samsung in 8nm (8N), which is not quite able to keep up with the 7nm node at TSMC (e.g. used by AMD and also for the professional GA100 Ampere chip).