Question: ROG Crosshair VII Hero and Vega 64 PCIe compatibility

[Snoffe]

I have a critical question concerning a build combination I am currently considering (check my first thread on the build forum). Before I make my purchase, I have to get this issue cleared or I will lose my mind.   I apologise if this is a double thread, but I could not find this question being asked before. See image below:

 

 

1. If I pair my planned Crosshair VII Hero (non-wifi) with Ryzen 7 2700X and Sapphire Nitro+ RX Vega 64, will the single top PCIe 3,0 slot run only in x8 mode? If I had, for example, RX 580 or 1070 Ti etc., it would run in x16 mode?

 

2. With the same combination, why does the board support DDR4 overclocking only upto 3200 instead of 3466 with non-Vega graphics cards?

 

Am I reading this right or am I a moron? If I am right, why is this happening and why are AMD/ASUS sabotaging themselves with top-of-the-line Vega models?

[bleedblue]

1. No. It wouldn't matter anwyay, it takes a Titan V to fully saturate even a x8 PCIe 3.0

 

2. That's system memory

 

 

[Snoffe]

2 minutes ago, bleedblue said:

1. No. It wouldn't matter anwyay, it takes a Titan V to fully saturate even a x8 PCIe 3.0

 

2. That's system memory

 

 

Thanks for the reply.

 

1. No, as in it will run in x16 with Vega and not x8 with Vega? Btw can you link good source about PCIe 3,0 saturation?

 

2. That's what I meant. Check the picture.

[Spotty]

"AMD Ryzen with Radeon Vega Graphics" in the memory and PCIe section refers to the Ryzen APUs which have integrated Vega graphics processors built in to the CPU. Such as the Ryzen 2200G with Vega 8 graphics.
It does not refer to Vega graphics cards such as the Vega 56 or Vega 64.

14 minutes ago, Snoffe said:

If I pair my planned Crosshair VII Hero (non-wifi) with Ryzen 7 2700X and Sapphire Nitro+ RX Vega 64, will the single top PCIe 3,0 slot run only in x8 mode? If I had, for example, RX 580 or 1070 Ti etc., it would run in x16 mode?

It will run in x16 mode if only the top x16 slot is occupied. If you occupy the top two x16 slots they will each run at x8 speed.
 

2 minutes ago, Snoffe said:

Btw can you link good source about PCIe 3,0 saturation?

Read these two articles. The first testing with the GTX 1080 is more applicable to your set up.
https://www.gamersnexus.net/guides/2488-pci-e-3-x8-vs-x16-performance-impact-on-gpus
https://www.gamersnexus.net/guides/3176-dual-titan-v-bandwidth-limit-test-x8-vs-x16

[Snoffe]

3 minutes ago, Spotty said:

"AMD Ryzen with Radeon Vega Graphics" in the memory and PCIe section refers to the Ryzen APUs which have integrated Vega graphics processors built in to the CPU. Such as the Ryzen 2200G with Vega 8 graphics.
It does not refer to Vega graphics cards such as the Vega 56 or Vega 64.

It will run in x16 mode if only the top x16 slot is occupied. If you occupy the top two x16 slots they will each run at x8 speed.
 

Read these two articles. The first testing with the GTX 1080 is more applicable to your set up.
https://www.gamersnexus.net/guides/2488-pci-e-3-x8-vs-x16-performance-impact-on-gpus
https://www.gamersnexus.net/guides/3176-dual-titan-v-bandwidth-limit-test-x8-vs-x16

Ah, so it refers to Ryzen with integrated Vega APU. Thank you for getting this cleared up! This marketing language was the source of my confusion then.

 

I am planning on running a single Vega 64, so the top slot will be x16 then. Thanks again for your reply!