RX 6600 XT the PCI x8 on Gen 3 issue

[Nena Trinity]

Ok so I looked around and it seems there is no issue at 4k and 1440p since then you are GPU bound, where the issue seems to be is at 1080 in CPU bound scenarios? My question is why?! Can someone please explain why?!! Most also tested on a Ryzen 7 5800 which begs a bigger question what the hell will happen to a Intel Core i5-9600K, Ryzen 5 1600AF & 3600? Or let's go mother of all lemons and use a 4790K or Pentium G3258? How bad can the PCI x8 be on PCI-E 3.0?

[8tg]

Not awful based on speculation. It’ll depend on a lot of stuff, we’ll see when the cards get into the hands of testers.

I was gonna say “AMD wouldn’t do anything stupid like gimp a product that hard” but I’m gonna not say that because they probably would.

I don’t think it’ll be that bad, you could run a 980ti on pcie 3.0 x8 without any performance loss, if this card is on par with a 980ti or even a little better I don’t see any issues.

[Nena Trinity]

15 minutes ago, 8tg said:

Not awful based on speculation. It’ll depend on a lot of stuff, we’ll see when the cards get into the hands of testers.

I was gonna say “AMD wouldn’t do anything stupid like gimp a product that hard” but I’m gonna not say that because they probably would.

I don’t think it’ll be that bad, you could run a 980ti on pcie 3.0 x8 without any performance loss, if this card is on par with a 980ti or even a little better I don’t see any issues.

It's faster than a GTX 1080 to be exact, plus it has 8GB VRAM like the 1080 so it's a good match. 

[Chris Pratt]

The card is designed for PCIe 4.0x8, which is equivalent to PCIe 3.0x16. If you put it in a PCIe 3.0 slot, the card only has half the bandwidth it should. That said, it may not matter in every game, but it will matter in some. Lower end cards like these often don't actually even need more than PCIe 3.0x8, in the first place.

 

I remember back when Digital Foundry did their PC performance review of Horizon Zero Dawn, when it first released. The reviewer was accidentally running x8, initially, and performance was improved when switching to x16. In that game, it did matter.

 

In short, you will have a built-in bottleneck, but depending on the game, it may or may not come into play.