Question Pairing a graphics card with a Ryzen-G (up to 5000 series) processor

[mikeymikec]

Hi all, I'm just wanting to make sure my knowledge is accurate!

If I was pairing a graphics card with a Ryzen non-G processor with a PCIe 4.0 board, then my choices wouldn't be limited by graphics card link speeds, ie. if I went with a lower-end graphics card with only an 8x link speed then I get its full performance (at least as far as link speeds are concerned).

If however I'm pairing an 8x link graphics card (e.g. a RTX 4060 or RX7600) with a Ryzen-G processor, then the Ryzen-G processor would limit the PCIe gen to gen3, so therefore the graphics card gets hobbled by PCIe 3.0 and its own 8x link speed.

Is this correct?

 

[SteinFG]

This is correct on AM4 (Ryzen 3000G, 4000G, 5000G).

All AM4 G series chips have PCIe 3.0, so with a card like 4060/7600 (Which have 8 PCIe 4.0 lanes), you'll get 8 PCIe 3.0 lanes.
Though, this won't limit your performance much, unless you're running out of vram.

On AM5, 8000G series chips have PCIe 4.0

 

[mikeymikec]

Weird, looking at benchmarks (even say HWUB which I'm 99% certain covered the issue I was concerned with), it's nowhere near as bad as I thought. I could have sworn that I previously saw performance drops of around 50%.

 

[DAPUNISHER]

Weird, looking at benchmarks (even say HWUB which I'm 99% certain covered the issue I was concerned with), it's nowhere near as bad as I thought. I could have sworn that I previously saw performance drops of around 50%.

That would be the RX 6400 and 6500XT which are only x4 cards.

 

[mikeymikec]

That would be the RX 6400 and 6500XT which are only x4 cards.

Ahha! I believe you're right, IIRC a 6650XT (or close enough) was involved.

 

[LightningZ71]

Keep in mind, a lot of the performance loss is related to running short on VRAM. If you dig enough, you can find comparisons between the 4GB 6500XT and the 8GB 6500XT (yes, they did exist, but were quite rare). Sometimes, there's not much difference, in others, it's rather drastic. Also, for the 6500 and 6400, they get hit really hard on the older APUs (prior to the 8000g series) because they are limited to PCIe3.0. It's really bad. It's so bad that the 8GB 5500XT is universally faster.