I found this interesting video:  https://www.youtube.com/watch?v=bP_8EYQ-2RA

I want to speed up my renders from Firefly and LuxRender.  So far, I have only done renders on a laptop, so I have no experience with using desktop GPU.  So here are some newbie questions.  Will this work?  How will the laptop know to switch to using the GPU rather than its own CPU?  Will I have to do anything to get the 3D rendering software to switch to using the GPU?

Firefly doesn't use GPU so no benefit, not attempted to use OpenCL with LuxRender for a couple of years so don't know what the support is like for current version

Looking at the implementation of the device there are a number of concerns,  looks like you will need to open up your laptop and plug this device in each time you need to use it, this runs the risk of bending or damaging the laptop connector so care will be needed. The graphics card will need to be powered, from the video it looks like a PC will be required for anything other than a very low powered GPU (if they exist), if you already have a PC why not use the PC directly for the rendering instead? The other problem is all the parts are exposed (laptop, PC, GPU) which means you'll have static sensitive components unprotected as well as the noise from the GPU fan, nothing to stop you from building an enclosure if this is the only problem.

Sorry if this is a bit negative but none above is a show stopper if you feel the risks are offset by the benefits.

As for compatability, the device is so unique I'm not sure anyone can answer that question unless they try the device itself, the video clearly shows it in use as a display for a game which I assume uses DirectX but don't know if that also means its compatible with OpenCL. If you have a contact for the supplier it might be worth asking them.

If you want to use an external GPU, you will need to use either the Octane Renderer (and a NVidia card), or Reality (to use LuxRender) - Firefly doesn't use a GPU to render.

I would recommend reading the documentation for either before you get too deep.

Using that adapter for GPU intense applications sort of defeats the purpose of having a High End Video card.

Most notebooks use a rather slow bus speeds and high processor stepping. The slow bus is the one reason that it is considerably slower than if it was on a desktop board.

If you want to use a notebook with a High End GPU, get a notebook that already has a High End GPU in it. High End GPUs in notebooks will never be as fast as a desktop, but one that has it built in will not loose as much as going external. If you do get a notebook with a decent GPU, make sure it has dedicated memory for the GPU. Shared memory will be DDR3, which is considerably slower than dedicated DDR5 video ram.

The video mentions checking to see if it is compatible, which means that there are probably more systems out there that it wont work on than ones that it will.

The other reason it is slower, has to do with the PCIe differences.

Very few notebooks have true PCIe slots. Most have ones that are variations of PCIe that do not match the PCIe standard. PCI express Mini is usually just a nerfed pci slot and a usb slot in the same plug. Some are a mix of sata and PCIe. Some are so proprietary, that nothing will work in it unless it is designed to.

Thank you all for your input.

Hello like you I use a laptop  I do have access to a Sony Desktop  but my laptop is very new   faster   alot more ram  24Gb  and runs at 3200  so my renders are not that slow    yes we all want faster computers  but the only thing I want to do is add an other VDU   for ease of work.... Ian////radioham