Is it worth it, to put a new GPU, in an 8 year old PC, just for ComfyUI usage ?

[JorgeR81]

Is it worth it, to get an RTX 5070 Ti, for this system ?
How bad would the CPU bottleneck be, in ComfyUI ?

I've build this PC in 2017, which was almost top-tier back then:

• CPU: Intel Core i7-7700 "Kaby lake" ( 4 cores, 8 threads )
• Motherboard: Asrock Z270 Taichi ( PCIe 3.0 )
• SSD: Samsung  850 PRO, 512 TB ( SATA SSD ) ( "MLC" nand ) ( 100% health )
• RAM: 32 GB ( 2 x 16 GB DDR4-2133 from Kingston )
• GPU: Asus GTX 1070 8GB Expedition OC
• Power supply: Corsair RM650x
• Case: Corsair Carbide 600Q 

I have Windows 10.
Windows 11 does not support Kaby lake CPU.
I'm considering switching to Linux, but I've never used it.

I don't play video games, so this is still fine for me. 
I just need more performance in ComfyUI ( mostly for faster Flux generations ).
The GTX 1070 it's fine for SD15 and SDXL, but very slow with Flux ( about 30 sec/it ).

[ltdrdata]

Since the GPU has the greatest impact on inference performance, upgrading it alone can lead to a dramatic improvement.
If you replace your computer in the future, you can simply move the GPU to the new system.

However, if you're upgrading to a high-end GPU, make sure that your case is large enough to accommodate it, and it's recommended to upgrade your power supply to one with sufficient capacity as well.

[Pingui080]

Why I would worry about the most is that you would be using a 50 series card in this case the 5070 ti which are PCIe gen 5 and your motherboard is only PCIe gen 3 so the bottleneck here won't be the cpu but the motherboard

[JorgeR81]

I don't do much gaming.
For the ComfyUI use case, I'm assuming that would only cause a slow down when models are being loaded to VRAM ( not during the KSampler stage ) ?