cancel
Showing results for 
Search instead for 
Did you mean: 
Reply
Cybertri
What's DOS?
Posts: 4
Registered: ‎04-29-2017
Location: US
Views: 8,563
Message 1 of 9

Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

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?

DreadfulDrummer
Punch Card
Posts: 22
Registered: ‎04-03-2017
Location: FI
Views: 8,503
Message 2 of 9

Re: Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

Everyone seems to be reporting 2 lanes.

Cybertri
What's DOS?
Posts: 4
Registered: ‎04-29-2017
Location: US
Views: 8,485
Message 3 of 9

Re: Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

 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.

DreadfulDrummer
Punch Card
Posts: 22
Registered: ‎04-03-2017
Location: FI
Views: 8,460
Message 4 of 9

Re: Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

I've never used a TB3 eGPU but I've shoved a GTX 960 through the neck of my Inspiron 15z's wireless card's mPCIe slot (which is x1, I believe) and was able to play most stuff like GTA V, Witcher 3, DOOM. I found anything CPU intensive suffered but everything else was just fine. Obviously, I wasn't expecting huge frame rates so I was happy with 30+ but I would be getting into the 50s and above in some titles. I'm thinking the GTX 1050 in the Yoga 720 would perform similarly to, if not better than, what I'm used to so I'd be happy with this laptop.

I would say a more powerful card, like a GTX 1080, would be crippled by the x2 bottleneck and would end up performing similarly​ to a weaker card which is why people say it's​ not worth it; it's not worth shelling out for a monster card only to gimp it with a x2 Thunderbolt 3 connection.
I don't know enough to make that claim but that would be my guess.
Highlighted
Cybertri
What's DOS?
Posts: 4
Registered: ‎04-29-2017
Location: US
Views: 8,446
Message 5 of 9

Re: Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

The 720 has a quad core i7. A 7700hq. Doesn't that count for anything?  Or still too weak to be useful?

DreadfulDrummer
Punch Card
Posts: 22
Registered: ‎04-03-2017
Location: FI
Views: 8,431
Message 6 of 9

Re: Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

When it comes to an eGPU, I can't rightly say. It's powerful and should bulldoze over any task up against which you put it but I don't know enough about eGPUs to answer that.
Anyone else? Any lurkers in the know?!
Gowtham91m
What's DOS?
Posts: 1
Registered: ‎05-03-2018
Location: US
Views: 3,054
Message 7 of 9

Re: Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

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?

UnixSu
What's DOS?
Posts: 3
Registered: ‎10-16-2018
Location: GB
Views: 1,669
Message 8 of 9

Re: Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

Hi,

 

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 

 

Capture.PNG

ingressum
What's DOS?
Posts: 1
Registered: ‎12-27-2018
Location: US
Views: 1,252
Message 9 of 9

Re: Yoga 720 13" & 15" Thunderbolt 3 PCIexpress lanes 2 or 4?

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.

Check out current deals!


Shop current deals

Top Kudoed Authors