Processors

[HLGM]

Now I am using a B650E motherboard with 7600X CPU to measure the PCIe Gen5 devices. Unfortunately, I find the PCIe Gen5 slot can not get up to full speed. It seems the PCIe Gen5 x16 slot has only x8 capability.

I configure the slot as x4x4x4x4, and connect 4 PM1743 SSD.

The first SSD is connected, I can get about 14GB/s IO throughput. Add the second SSD in system, the throughput can be up to 29GB/s or so. When I add one more SSD again, the IO throughput will still be 29GB/s. Even if I connect 4 SSDs, the IO throughput is also 29GB/s. OS can detect all 4 SSDs and LnkStas are all 32G x4. So it looks the 7600X PCIe Gen5 x16 slot has only a x8 capability.

I am not sure how method can help to improve the PCIe slot up to real x16 capability?

[johnnyenglish]

Hi, i'm sorry to ask but just to be sure. 

You are using the integrated GPU only right? Because if you are using a dedicated graphics card then its normal to get 8x.

Even if the board says on the manual that both PCIe slots have 16x capability. You still have to share lanes. 

If you don't have a dedicated card, then it could be the nvme card itself. Not sure. 

Good luck 

[HLGM]

Thanks so much, man. Yes, I am using the integrated GPU instead of dedicated graphics outside of CPU. I am not sure if the integrated GPU shared the x16 lanes in CPU design. 

Best Regards, 

HLGM

[HLGM · Accepted solution]

Thanks so much all. I have solved the problem. Now PCIe slot can have a very good IO throughput. 

Two DIMMs are key action.