EGPU bottleneck?

[kelvinhall05]

I was interested in possibly doing an egpu mod using the pcie slot for the wifi card on my laptop, and was wondering what is the most powerful gpu that I can run without a psu (using only power from the pcie lane) without bottlenecking an amd a6 3400m. Is it even worth it? I got the laptop for free.

[MorganO]

2 minutes ago, kelvinhall05 said:

I was interested in possibly doing an egpu mod using the pcie slot for the wifi card on my laptop, and was wondering what is the most powerful gpu that I can run without a psu (using only power from the pcie lane) without bottlenecking an amd a6 3400m. Is it even worth it? I got the laptop for free.

probably not worth it

[System Error Message]

It depends on the game. I used to game on a core2duo laptop with a gtx 580 attached to the expresscard slot. Some games worked well, some games had fps drops. It was however a big improvement to the laptop's onboard nvidia GPU though which even though was a quadro that i could clock the shaders more than twice as fast and could play skyrim it had limited vram too.

[kelvinhall05]

4 hours ago, KOMTechAndGaming said:

probably not worth it

Kinda figured that

[-rascal-]

The problem isn't about the power -- you can rig up a regular ATX PSU to power the e-GPU -- BUT the neck-breaking (worst than bottlenecking) bandwidth a typically WiFi expansion slot will have. PCI-E X16 3.0 can transfer up to ~16 GB/sec (yes...Gigabytes). You are not going to get anywhere close with a typical WiFi expansion slot -- probably not even PCI-Express 2.0 X8 speeds.

[Mira Yurizaki]

While graphics cards have been shown to not suffer serious performance losses until you subject them to PCIe 1.1 8x speeds or lower, most mini-PCIe slots on a laptop are of the x1 variety, probably 2.0 x1. Or PCIe 1.1 x2 speeds.

 

But given that you have a not-so-powerful CPU in there, a lower end card might not suffer as much.

[kelvinhall05]

35 minutes ago, M.Yurizaki said:

While graphics cards have been shown to not suffer serious performance losses until you subject them to PCIe 1.1 8x speeds or lower, most mini-PCIe slots on a laptop are of the x1 variety, probably 2.0 x1. Or PCIe 1.1 x2 speeds.

 

But given that you have a not-so-powerful CPU in there, a lower end card might not suffer as much.

 

How low end though? Some people think cards that cost 300usd are low end (JayzTwoCents!)

[Mira Yurizaki]

19 minutes ago, kelvinhall05 said:

How low end though? Some people think cards that cost 300usd are low end (JayzTwoCents!)

Eh, I rarely take his words seriously. I find him someone who sipped too much PCMR holy water.

 

Anyway, like in the $100-$150 range.

[kelvinhall05]

Just now, M.Yurizaki said:

Eh, I rarely take his words seriously. I find him someone who sipped too much PCMR holy water.

 

Anyway, like in the $100-$150 range.

 

So would something like a 950 mini (it's 75w, pcie power only) bottleneck even through the x1 slot?

[Mira Yurizaki]

36 minutes ago, kelvinhall05 said:

So would something like a 950 mini (it's 75w, pcie power only) bottleneck even through the x1 slot?

Probably, but not as bad as a GTX 1060 or higher

[System Error Message]

used to be a $300 GPU was high end. i can tell you for a fact that i have gamed on PCIe 1.1 x1 on a gtx 580, that would be considered high end at that time, coupled with a core2 CPU. Sure it does have its bottlenecks but compared to onboard while still having the option of portability is a big increase.

 

It also depends on the GPU too as nvidia GPUs are better at this than AMD. If your laptop has intel HD graphics and the slot is x1 than nvidia optimus has some sort of compression that gives it an equivalent of an x4 slot. The resource usage as well (if you google and read the main egpu guide/thread at another forum) there is a hardware resource allocation requirement too.

 

As long as it uses PCIe (even if it is mini PCIe) than it will work. The bottleneck mainly depends on the game you play.

[kelvinhall05]

38 minutes ago, System Error Message said:

used to be a $300 GPU was high end. i can tell you for a fact that i have gamed on PCIe 1.1 x1 on a gtx 580, that would be considered high end at that time, coupled with a core2 CPU. Sure it does have its bottlenecks but compared to onboard while still having the option of portability is a big increase.

 

It also depends on the GPU too as nvidia GPUs are better at this than AMD. If your laptop has intel HD graphics and the slot is x1 than nvidia optimus has some sort of compression that gives it an equivalent of an x4 slot. The resource usage as well (if you google and read the main egpu guide/thread at another forum) there is a hardware resource allocation requirement too.

 

As long as it uses PCIe (even if it is mini PCIe) than it will work. The bottleneck mainly depends on the game you play.

 

Planning to play Beamng.Drive, maybe GTA V, and TF2

[System Error Message]

tf2 works well even on IGP. But all those games would benefit from eGPU. Its more of a cost benefit thing. You need a PSU, adapter and monitor.

 

So you can expect to get less bottleneck with those games.

[System Error Message]

i should add that i did have some posts about egpu on the lenovo forums. The older thinkpad series with the full dock, the dock itself was capable of a GPU that pulled 50 watts from PCIe and the laptop had an expresscard slot. With a GPU that has onboard nvidia i was able to have a total of 3 GPUs including onboard. I have ofcourse experiemented various GPUs on the laptop and tricks to get them working.

 

On another forum there is an egpu thread (googling is easy to find it) with a chart on the best situation for each GPU.