eGPU Discussion

[NovHak]

@fevieira I agree with you. In fact I've not been precise enough, my point is that if I want a laptop with the best performing card, 16GB RAM, 2TB disk, current generation Core i7, and easily maintainable, I will pay 50% more than what I paid in 2014.

I started my search with that in mind, but now I'm thinking about making some compromises, such as getting a 2070 Super (non Max Q). Going below 2TB may be difficult, as I've been used to it now

I'm eager to see some progress in the domain of eGPUs. Currently it's still a pain because laptops aren't yet designed with that in mind (and Windows is still lagging behind in terms of eGPU support), but hopefully it will come in a few years...

 

[FerrariVie]

I'm eager to see some progress in the domain of eGPUs. Currently it's still a pain because laptops aren't yet designed with that in mind (and Windows is still lagging behind in terms of eGPU support), but hopefully it will come in a few years...

I sincerely doubt that it is getting better anytime soon. As years go by, it's only getting worse and the reason for that is not the laptop itself, but how the desktop GPUs are being designed to have better performance: just throw in a lot more power. And that is not something that a laptop can support.

If nothing changes, even desktops will reach a maximum at some point in the future, when GPUs start needing 1000W. Until nvidia starts focusing on efficiency, it will only get worse for laptops, unfortunately.

 

[NovHak]

As far as eGPU setups are concerned, power generally isn't provided by the laptop itself but by a separate PSU, so in that sense, power isn't a problem. That being said, concerning the elecricity bill it's another matter...

 

[FerrariVie]

As far as eGPU setups are concerned, power generally isn't provided by the laptop itself but by a separate PSU, so in that sense, power isn't a problem. That being said, concerning the elecricity bill it's another matter...

I get what you mean, but the problem here is really what too much power causes: heat! 🔥 What I'm saying is that 150W that the (rare) 2080 mobile uses is already too much heat for a laptop to dissipate, imagine going beyond that? Only water cooling would make that happen.

 

[NovHak]

I thought the 2080 Mobile was another name for the laptop version of the 2080, the one before the 2080 Super ? So that's why I didn't see the term often...

But anyway I don't get you, the e in eGPU means external, the cooling would be external too, since it's meant for using GPUs that can't fit in a laptop... or did I miss something ?

 

[SpyderTracks]

I thnk @fevieira is missing what an eGPU is.... my guess is the GPU will become modular in laptops within a few years and you'll use on board for being mobile and attach the eGPU when needing to game.

eGPU's are already pretty decent, they've come a long way in the last couple of years, the Razer Core X is the one to beat by a long way I think, you'll get about 80% of the overall GPU power translated which is going to max out almost any laptop screen:

Buy Razer Core X Chroma | Gaming Egpus | Razer.com

Purchase Razer Core X Chroma (gaming egpus), or browse through our extensive selection of gaming peripherals, and more at razer.com

www.razer.com

 

[NovHak]

It's still not enough, from what I understand, the 20% loss in performance is due to lack of Windows support + the need to mirror the display if one wants to use the laptop display, which should be the goal imo. Having a big GPU standing near the laptop is one thing, but seriously, needing an additional external monitor is another. I may be able to bring the eGPU along with my laptop, but not an external monitor.

Thunderbolt I/O becoming more common and devices such as the Razer Core X have helped, but not enough for me yet !

Hmmm... now that I think of it, isn't this going off-topic ?

 

[SpyderTracks]

It's still not enough, from what I understand, the 20% loss in performance is due to lack of Windows support + the need to mirror the display if one wants to use the laptop display, which should be the goal imo. Having a big GPU standing near the laptop is one thing, but seriously, needing an additional external monitor is another. I may be able to bring the eGPU along with my laptop, but not an external monitor.

Thunderbolt I/O becoming more common and devices such as the Razer Core X have helped, but not enough for me yet !

Hmmm... now that I think of it, isn't this going off-topic ?

Good point, I’ll move to its own thread cos it’s an interesting topic.

I wasn’t aware you needed an external screen to get the most out of it, yeah, that’s a bit of a deal breaker, definitely further to go!

 

[FerrariVie]

Good point, I’ll move to its own thread cos it’s an interesting topic.

I wasn’t aware you needed an external screen to get the most out of it, yeah, that’s a bit of a deal breaker, definitely further to go!

I did miss the e when reading, so was still thinking that @NovHak was talking about laptop GPUs, as his previous posts on the old thread 😜

Great that you created a new thread for this specific topic

 

[SpyderTracks]

I did miss the e when reading, so was still thinking that @NovHak was talking about laptop GPUs, as his previous posts on the old thread 😜

Great that you created a new thread for this specific topic

eGPU's are quite an interesting topic that not many people are aware of. There are certain uses where it makes a lot of sense although it's certainly stilll niche.

 

[RicDin]

Just stopping by to add that the current eGPU setup's main pitfall is simply bandwidth. With the hard limit of 4x PCIe 3.0 at most (4*8 Gb/s) there comes a point where it simply is not possible to compete with the 12x to 16x you find on desktop motherboards.

Adding to that the laptop bus is often shared for these connections so anything besides the eGPU "packets" further throttle these limits. In practice, most hardcore eGPU people have managed to achieve a stunning ~22 Gb/s over Thunderbolt 3 or over one of the memory slots. This means that, until a couple of iterations from now, the eGPU will decently increase performance with dimishing gains as it nears a 4k resolution/increased fps combo.

 

[NovHak]

Interesting... However, correct me if I'm wrong, but I suppose people using an external display can thus save on bandwidth ?

If there was a way to plug the eGPU output in such a way that it's Optimusified, if you see what I mean, shouldn't that get more bandwidth for people using their laptop's display ?

 

[RicDin]

Interesting... However, correct me if I'm wrong, but I suppose people using an external display can thus save on bandwidth ?

If there was a way to plug the eGPU output in such a way that it's Optimusified, if you see what I mean, shouldn't that get more bandwidth for people using their laptop's display ?

Exactly your eGPU's display should always be external to minimize the impact on this bottleneck.

A 4k frame should be about 265 420 800 bits per frame. At 60 fps you get 15 925 248 000 b/s plus the overhead. So ~14.83 Gb/s + overhead. If you offload some of this to an external display you save a lot of course, but you still need to render textures, models, effects, etc. which also amount to a sizeable chunk of data.

So we can extrapolate, without getting into the details of it, that at some point you will reach the limits of the pratical 22 Gb/s you can use. Not sure what you mean by Optimusified.