[SOLVED] Will Ryzen 5 3400G limit a video card to PCIe 8 lanes?

ManOfArc

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Jul 8, 2017
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Building a budget PC for someone. Just realized the CPU we ordered (Ryzen 5 3400g) was limited to 8 lanes PCIe. Is this true? Will it make a difference gaming with a RX 5500 XT at 1080p?
 

ManOfArc

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Thank you for clearing that up.
What is the max graphics card that would not be crippled at PCIe 3.0 x8? Assuming the CPU wasn't the weak link, that is.
 

InvalidError

Titan
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Currently no cards would be crippled, even a 2080ti would only lose a few frames.
The 4GB RX5500 does get crippled by 3.0x8: upgrading to a platform with 4.0x8 gives it 20-50% more performance in VRAM-constrained cases. Higher-end GPUs don't suffer as much because they have more VRAM and therefore don't need to hit system memory anywhere near as much.

Also, the RX5500 only have a 4.0x8 PCIe interface, so it would be limited to x8 regardless of CPU.
 

bignastyid

Titan
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The 4GB RX5500 does get crippled by 3.0x8: upgrading to a platform with 4.0x8 gives it 20-50% more performance in VRAM-constrained cases. Higher-end GPUs don't suffer as much because they have more VRAM and therefore don't need to hit system memory anywhere near as much.

Also, the RX5500 only have a 4.0x8 PCIe interface, so it would be limited to x8 regardless of CPU.
Interesting.
https://www.pcgameshardware.de/Radeon-RX-5500-XT-8G-Grafikkarte-275704/Specials/PCI-Express-3-vs-PCI-E-4-GPU-1339415/

Looks like you'd just have to lower the settings to reduce vram usage, likely you normally would when you are vram limited. Seems 4.0 bandwidth just helps with the performance hit when the card runs out of vram and has to use system ram.
 

InvalidError

Titan
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Looks like you'd just have to lower the settings to reduce vram usage, likely you normally would when you are vram limited.
Or if you look at the Far Cry results in your link, with 4.0, you don't need to lower details in the first place since it performs nearly as good as the 8GB version.

As I have written multiple times before, we're at a point where 4.0x8 if not 4.0x16 will become mandatory for 4GB GPUs to remain viable.
 

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