04-29-2017 01:09 AM
If you want to use an eGPU you need 4 lanes of PCIexpress otherwise the loss is too great for it to be worth it. But you only lose about 10% of the original power if you have 4 lanes of PCIexpress through Tuhunderbolt 3. So, what do the 13" and 15" models offer for the number of PCIexpress lanes?
04-29-2017 08:25 AM
Yep. That's what I have seen as well. But you know what? I also hear that 2 or 4 lanes doesn't make much difference. But the power of the CPU makes a huge difference. I'm trying to verify this since the Yoga 720 has a quad core cpu.... may be it would work well with an Akitio node and a GeForce 1080. I also read that disabling Optimus when using the eGPU matters.
04-29-2017 03:42 PM
04-30-2017 12:52 AM
05-03-2018 07:36 AM
Well, CPU power makes difference seems obvious. what if i have same CPU. how big the differennce would be from 2 lanes to 4 lanes keeping all other parameters constant?
10-16-2018 10:37 PM
It looks like my Yoga 15 i5 8th GEN is using 4 PCI Lanes. Please see screenshot I took whilst using my HP Omen Accelerator e-gpu and correct me if I am wrong
12-27-2018 03:19 AM - edited 12-27-2018 03:22 AM
This case is normal. I bet you have only iGPU (no GTX 1050) in your laptop. x4 lanes of PCIe are free and Lenovo decided to wire x2 free lanes to Thunderbolt 3 port. In general U-series CPU provides 12 lanes of PCIe through PCH. The distribution of them looks like this: x1 to PCH-CPU interconnect, x1 to WLAN, x4 to NVMe, x4 to GTX 1050 and after all only x2 are remaining available. So only two lanes provided to Thunderbolt 3. Since availability of x2 or x4 doesn't make much sense according to several tests better consider dGPU over eGPU, imho.