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external GPU for the Retina Macbook?

T

triple-tap

macrumors 6502
Original poster
Feb 18, 2013
265
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Today, Razor announced a new laptop with an interesting feature - a Thunderbolt 3 external graphics card dock, the "RAZOR CORE."

http://www.razerzone.com/gaming-systems/razer-blade-stealth#razer-core-specs

I have no desire to switch to a windows-only laptop, but I thought this was quite interesting. I am wondering how this would work on a retina Macbook (and hopefully the 2016 rMBP if they add a usb-c / TB3 port).

What are you thoughts?
 
As you indicated at the end, this will require Thunderbolt 3. That's what the Razer is using. The current generation is an obvious no-go for an external GPU.

I've read some posts of some success with external GPU on MacBook Pro's. But IMO, it's not really worth the time and effort to hack it.
 
whiteonline said:
As you indicated at the end, this will require Thunderbolt 3. That's what the Razer is using. The current generation is an obvious no-go for an external GPU.

I've read some posts of some success with external GPU on MacBook Pro's. But IMO, it's not really worth the time and effort to hack it.
Click to expand...

That is another part of my questions, I guess. How much difference is there between the USB-C in the current rMB vs. a TB3 ?
 
From how understand it, USB-C is not a protocol change. It's a standards change that brought USB-3.1 (10 Gbps) coupled with higher power in a single reversible connector.
Thunderbolt 3 (40 Gbps) is a different protocol in which USB can be transported within. They share the same USB-C connector. This allows TB3 ports to service USB-x devices. Same connector promotes acceptance.
 
USB-C is more about the cable and connector. It is meant to be a more universal cable/connector. That's why it can be used with Thunderbolt and carry DisplayPort over it. Thunderbolt is a completely different beast and should be compared to USB, the best version to compare it to would be the new USB 3.1 Gen2 since this one has nearly all of the Thunderbolt capabilities. The difference lies in bandwidth and how they do things.

Btw, USB3.1 isn't simply "10 Gbps" as it consists of Gen1 and Gen2. USB 3.1 Gen1 is simply USB3.0 and will only do 5Gbps. Gen2 is the one being able to do 10Gbps. Unfortunately Apple made the choice to only use Gen1 on the MacBook, it's just a USB3.0 port with a different connector (USB-C) and an upgraded version number (3.1). If you compare that to TB3 the difference is huge.
 
If the second gen rMB supports Thunderbolt 3 then I see no reason why it wouldn't work with Razer Core.

But I assume it needs to run Windows and have some drivers from Razer to take full advantage of it.
 
crsh1976 said:
Wouldn't the Core M chip bottleneck the GPU tho (if it'd work, that is)?
Click to expand...
It would be a bottleneck if the goal is running AAA games at maximum detail and resolution. But for casual use, the eGPU would drastically improve the performance even when coupled with Core M.
 
whiteonline said:
It would be a bottleneck if the goal is running AAA games at maximum detail and resolution. But for casual use, the eGPU would drastically improve the performance even when coupled with Core M.
Click to expand...
I seriously would have this verified first, given the Core M processor is not actively cooled and throttles whenever the heat goes up...
 
crsh1976 said:
I seriously would have this verified first, given the Core M processor is not actively cooled and throttles whenever the heat goes up...
Click to expand...
I'm not an expert but I think this is highly task dependant. If you're working on GPU intensive tasks doesn't that mean that most of the heat is generated by GPU which in this case is external, meaning minimal CPU throthling. In other hand, if you do highly CPU intensive tasks I don't think rMB is a right choise to begin with.
 
Skylitfly said:
I'm not an expert but I think this is highly task dependant. If you're working on GPU intensive tasks doesn't that mean that most of the heat is generated by GPU which in this case is external, meaning minimal CPU throthling. In other hand, if you do highly CPU intensive tasks I don't think rMB is a right choise to begin with.
Click to expand...

Correct. It all depends. ;)

I agree, and as I noted earlier - it's most likely not with the effort to do this.
 
The entire purpose of a GPU is to offload certain tasks so the CPU can do other things. The CPU will still have some effect on this but not so much that it will throttle the GPU. The PCIe speed will be more likely the culprit. In case of the Core M there will be a benefit by offloading things to an external GPU. The internal GPU isn't being used or very little. That means it will run cooler which in turn means it won't throttle as quickly. We've already seen something similar happen with notebooks hooked up to an external display: using them in clamshell mode will make them a bit faster because the internal display is not in use (the GPU will drive only 1 display instead of 2).

There is another thing we need to keep in mind. A system consists of more components and they all have to work together. The system is as fast as its slowest component. So yes, the GPU might be fast but if the CPU is also being used you may still end up with slow running software if it can't keep up.

Even if the Core M in the MB isn't able to keep up with a mid to high end GPU you still benefit, especially if you use an external display. The eGPU could drive a 27" 5k display without any problems whereas the GPU in the Core M might be running on its toes (if it is even capable of running it at all). That alone can make an eGPU worth it.
 
I think the hope is if the next gen rmb has tb3 then it'd have sky lake as well.
 
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