Question Could I run an external GPU this way?

[Tad2]

I have an alienware r3 15 laptop. It has no mini pcie slots.
but it does have a bunch of m.2 slots.

I've used desktop gpu's in the past via mini pcie adapters (on a laptops mobo) and it works great.

Would my alienware recognize a graphics card through an m.2 slot?
I found some m.2-mpcie adapters on amazon for pretty cheap.

So I could run laptopmobo - m.2 - mpcie - desktop gpu

 

[kerberos_20]

if we put bios issues aside, your main concern would be power draw
GPUs usualy draws up to 75 watts from PCIE slot, while M.2 slot offers up to 25 watts, your adapter (m.2 to pcie/mpcie) will need to have power supply attached
something like this
https://www.amazon.com/H-COME-PCI-Express-Powered-Cable-GPU-Adapter-Ethereum/dp/B076F47VYV

 

[Tad2]

if we put bios issues aside, your main concern would be power draw
GPUs usualy draws up to 75 watts from PCIE slot, while M.2 slot offers up to 25 watts, your adapter (m.2 to pcie/mpcie) will need to have power supply attached
something like this
https://www.amazon.com/H-COME-PCI-Express-Powered-Cable-GPU-Adapter-Ethereum/dp/B076F47VYV

woah! I sidnt know those existed. That is way better. No need to adapt, because it goes directly from m.2 to the gpu.

on the power issue, the gpu would be plugged into its own psu, so wouldnt that solve any power draw issues?

 

[kerberos_20]

not really, pcie provides up to 75watts, pcie connectors provide rest gpu needs, power is defined in gpu bios/board layout, unless u change it/or dyi some circuits, to limit pcie slot to 25watts/cut power, then ull just get instability issues

for example 1080ti uses it for memory controller

here u can see that memory wont get any juice from external power supply

 

[Tad2]

Ooohhhh ok. I should be careful which one I get then. I saw a youtube video where someone accomplished it with a m.2-pcie4x adapter.
That product was designed for gpu's in mind though.
I suppose if I could find that one i'd just get that, but I was just planning on getting the cheapest thing... :\

I've done this a lot with mini pcie slots on other systems. It worked totally fine. Although that was only pcie 1x. (you'd be surprised how little performance you lose at only 1x btw).

So am I right to assume that all m.2 slots only give out 25watts? And desktop gpu's need more than that from their slot?

 

[kerberos_20]

pcie is usaly wired as follow:
pcie x1 - 10watt
pcie x4 - 25watts
pcie x16 - 75watts

m2 is usualy x4

 

[Tad2]

I had no idea. So how do you know how many watts a gpu actually needs from its pcie slot? Internet info usually only talks about psu requirements. Or tdp.

 

[kerberos_20]

that depends on how many ram chips and memory type it has, how many memory controllers it has, and slightly on vrm quality

 

[Tad2]

Hmmmm I'm going to guess it doesn't matter to be honest.
People run every kind of gpu out there on pcie 1x without any problem.
And that has LESS than the m.2.
So doesn't that mean that the m.2 setup would actually be preferable over an mpcie setup? (concerning the voltage issue)

 

[Tad2]

So I found out that it works totally fine.
Basically the m.2/pcie expansion adapter cards have a power cord built in. So you plug in your molex or whatever
to it from a power supply.