ASUS G751JY running it's TB2 controller at half speed
 
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ASUS G751JY running it's TB2 controller at half speed  

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SamuelFDias
(@samuelfdias)
New Member
Joined: 4 years ago
 

Hello there my fellows. 

I own a ASUS G751JY and this days I started to think in create my  own eGPU station. But when I start to dig a little more I found the hard true... TB2 only runs at half of the speed as you can see for your self.

 

 

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

.

nando4 liked
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nando4
(@nando4)
Noble Member Admin
Joined: 4 years ago
 

I'll add this underperformance cannot be fixed with say a BIOS fix.

The G751JY is definitely missing 2 electrical lanes attached to it's TB2 controller since it's hosted off port1 and wifi is on port3 (0:1c.2). With the series-8 chipset used there, the wiring of port3+4 would become port1's lane3+4 if port1 was reconfigured to x4 2.0 mode by an updated BIOS.

eGPU Setup 1.35    •    eGPU Port Bandwidth Reference Table

 
2015 15" Dell Precision 7510 (Q M1000M) [6th,4C,H] + GTX 1080 Ti @32Gbps-M2 (ADT-Link R43SG) + Win10 1803 [build link]  


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Yukikaze
(@yukikaze)
Prominent Member Moderator
Joined: 4 years ago
 

That is an annoyance, indeed. That said, things will still work. This is still equivalent to a Thunderbolt1 link, and I am getting decent results with that on my T430s. But it is definitely not reassuring that we now need to not only check for overall eGPU capability, but also for the actual amount of lanes because manufacturers are cutting corners. This is board design 101: Make sure that a component rated for X bandwidth downstream has at least an X bandwidth in the upstream. Grr.

Want to output [email protected] out of an old system on the cheap? Read here.
Give your Node Pro a second Thunderbolt3 controller for reliable peripherals by re-using a TB3 dock (~50$).

"Always listen to experts. They'll tell you what can't be done, and why. Then do it."- Robert A. Heinlein, "Time Enough for Love."

 
2012 14" Lenovo Thinkpad T430s [3rd,2C,M] + RX 550 @ 10Gbps-TB1 (Atto Thunderlink) + Win10 [build link]  


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nando4
(@nando4)
Noble Member Admin
Joined: 4 years ago
 

Annoyance indeed. Here the TB2 link, running at x2 2.0 brings it down to 8Gbps. TB1 connects electrically at x4 2.0, but is limited by the TB1 controller to 10Gbps, so is actually faster. 

 

These are gaming machines with a already powerful GTX980M running a full PCIe bus.  For someone used to gaming performance, I wouldn't recommend spending the time and money to get an eGPU working on this system. Rather, consider asking Asus for a G752  replacement due to underadvertised performance. G752 with a TB3 controller. If it too is running at half speed then will get the 16Gbps paid for on the G751.

Posted by: Yukikaze

 

That is an annoyance, indeed. That said, things will still work. This is still equivalent to a Thunderbolt1 link, and I am getting decent results with that on my T430s. But it is definitely not reassuring that we now need to not only check for overall eGPU capability, but also for the actual amount of lanes because manufacturers are cutting corners. This is board design 101: Make sure that a component rated for X bandwidth downstream has at least an X bandwidth in the upstream. Grr.

   

eGPU Setup 1.35    •    eGPU Port Bandwidth Reference Table

 
2015 15" Dell Precision 7510 (Q M1000M) [6th,4C,H] + GTX 1080 Ti @32Gbps-M2 (ADT-Link R43SG) + Win10 1803 [build link]  


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