Asking for a friend... but wish it was me that had the 2070
Gaming at only 1080p... Would the RTX 2070 be bottle-necked by the 4c/8t Ryzen (considering it's only using 8 lanes)?
If so, would running at 1440p make any difference?
The Ryzen 3400g was designed primarily for gaming using its integrated graphics. Due to the low-powered nature of the integrated graphics on this chip (compared to dedicated GPUs) the CPU was designed with low frame rates and low processing needs in mind (hence things like the PCIe x8 interface). It was never designed to support the kind of frame rates capable of being pushed by a RTX 2070. Not only is 4C/8T considered the bare minimum for most modern games, but the 3400g has low boost clock speeds as well.
While pairing a 3400g and a RTX 2070 is kind of like putting used knockoff-brand tires on a Luxury-brand car, it might still be an acceptable pairing depending on what kind of games your friend plays and at what frame rates:
- The more graphically demanding a game is, generally the more work required by the CPU to pre-render frames for the GPU. Example: Cyberpunk 2077 requires a much more powerful CPU to be able to run at a smooth 60 fps than Valorent does. If your friend wants to play modern AAA games, the 3400g will heavily bottleneck the RTX 2070.
- The higher your target frame rate is, the quicker your CPU has to pre-render frames it sends to the GPU. Depending on the game, most anything above 60 fps will be difficult if not impossible at times to achieve with a Ryzen 3400g.
It's difficult to overstress how much your friends game choice and desired frame rates will impact how much a 3400g will bottleneck a RTX 2070. What games does he want to play with this combination? Does he want a locked 60 fps? Higher than 60 fps?
And as far as 1440p in concerned, 1440p only runs better for certain hardware combinations because with everything else being equal (the same game with the same quality settings) gaming at 1440p will result in a lower number of frames per second compared to gaming at 1080p due to the higher load on the GPU that the extra resolution places. Lower fps means a lower pre-rendering workload being placed on the CPU; in builds with somewhat underpowered CPUs, this can prevent the CPU from being the bottleneck in the rendering pipeline.
However, in this situation, the 3400g is so significally underpowered for a RTX 2070 in many games at 1080p that if you are CPU limited in a game at 1080p, more than likely you will still be CPU limited at 1440p. Keep in mind that the RTX 2070 was designed as a decent 1440p GPU in its day; running most games at 1440p won't be a taxing enough workload for it to prevent the 3400g from being the part in the system that limits your friend's framerate.