GPU TB3 expansion box recommendation: 1) >=60W charge, 2)if relevant/possible/he...
 
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GPU TB3 expansion box recommendation: 1) >=60W charge, 2)if relevant/possible/healthy a daisy chain slot, 3) very high wattage, 4) silent!  

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cmm
 cmm
(@mois)
Trusted Member
Joined: 2 years ago
 

Hi,

Which TB3 GPU expansion box do you recommend?

I want it to..

  • Feed my laptop with >= 60W charge current, so that the box would charge even a 15" laptop, hence no need to occupy another TB3 USBC connector with a laptop charger.
  • If there are any GPU boxes out there with a daisy chain connector then why not buy it?.. I guess this could be positive maybe, even if it's disallowed for eGFX/eGPU certification.
  • I may run a Vega 64 in this box, so there must be support for very high wattage.

    If needed I can buy a new PSU for the box. E.g. the Breakway Box, the Akitio Node Pro, and others, have SFX PSU:s, I could buy another stronger one

  • As silent as possible in web/office/video playback use.

    If the PSU would be a problem, there is some fanless SFX PSU out there e.g. Silverstone NJ450-SXL,  https://www.anandtech.com/show/13019/silverstone-launches-nj450sxl-psu-fanless-sfx-l-450whttps://www.silverstonetek.com/product.php?pid=797 .

What chassi do you recommend?

Sonnettech Breakaway 650 and maybe Akitio Node Pro seem interesting, maybe there are more.

I bought the Asus XG Station Pro by accident - it does not charge the laptop, duh (15W). Buying the wrong box is easy. Any recommendations would be very much welcome, thanks !!!

(Crossposted with  https://www.reddit.com/r/eGPU/comments/92esmu/gpu_tb3_expansion_box_recommendation_1_60w_charge/ .)

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts


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joevt
(@joevt)
Noble Member
Joined: 2 years ago
 

The eGPU.io Buyer's Guide lists all eGPUs with the power they supply to the eGPU, the number of Thunderbolt 3 ports, and the type of power supply. I think you're going to need to compromise as none of the options have two Thunderbolt 3 ports and supports at least 85W of charging. If 60W is ok with you then the AKiTiO Node Pro looks like the only option with two Thunderbolt 3 ports. Vega 64 may require GPU power higher than 375W (two 8 pin connectors) up to 475W (some OC cards may require even more so you should think about a higher power PSU (600W in an AKiTiO Node Pro should cover any Vega 64 up to 500W except those with three 8 pin connectors (525W) which will require a PSU of something like 650W). Sonnet has an extensive list of supported graphics cards which you can maybe adjust for the eGPU you choose assuming the reason a graphics card is not supported is only power related.

The buyer's guide charts don't have noise readings. You'll have to read the reviews for that information (if the reviewer mentions it). Changing the power supply will change the noise level though.

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case


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cmm
 cmm
(@mois)
Trusted Member
Joined: 2 years ago
 

@joevt , thanks for responding.

After careful consideration, I think the Razer Core X must be optimal for my usecase:

 * It has an ATX PSU, and I can easily find a fanless ATX PSU that can drive even the Vega 64. So I realize that ATX is a strong point for an eGPU chassi. This way, Core X is silent and powerful.

 * It has 100 watts laptop charge, which is excellent. 100 watts is pretty much the highest an USBC Thunderbolt 3 cable can carry.

 * Core X is common-sense, it does exactly only the eGPU function, nothing more. This should also be a performance guarantee. And it looks good.

Other TB3 peripherals should be connected to a separate TB3 connector on the laptop, so they get the 10gbps separate bandwidth that a dual-port TB3 controller exports, so in this model eGPU gets 22gbps and peripherals 10gbps. (High-end quad-core laptops such as Macbook Pro 15" has two TB3 connectors, so they have double what I just described, split over four TB3 connectors.)

     

Second-best option should be the Sonnettech Breakaway Box 650 or 550. It's lighter, slightly smaller, has high laptop charge too (87W), but the PSU is of the SFX kind and there are fewer options for those on the market, so I would be less sure that I can drive the Breakaway Box with a Vega 64 while fanless.

The Razer X is very heavy, however the computer display is very heavy also, so mobility is not an argument here anyhow.

   

(From talking to people, I understand that you should not daisy chain your eGPU, because the eGPU needs its 22gbps bandwidth already badly. Except for that however TB3 daisy chaining appears to work well.)
   
If you have any thoughts or comments on this analysis please let me know! 🙂

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts


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cmm
 cmm
(@mois)
Trusted Member
Joined: 2 years ago
 

@joevt , I realize actually I don't understand how much PCIe data bandwidth is available in sum on both Thunderbolt 3 ports on a dual-port Thunderbolt 3 controller, so I can't really reason about the tradeoffs in choosing between daisy-chaining versus connecting devices to two TB3 ports, see  https://egpu.io/forums/which-gear-should-i-buy/for-gpu-tb3-box-with-daisychain-connector-daisychain-ssd-ethernet-after-gpu-vs-connect-ssd-eth-to-laptops-second-thunderbolt-whats-the-speed-difference/ , if you have any thoughts please let me know.

Also, I realize that there can be situations where a daisy chain connector *can't hurt*. Maybe there are some moments when you need to run two bus-powered Thunderbolt devices at the same time, and you have your eGPU connected to your laptop, and your laptop has only two TB3 ports.

Therefore, if there was a chassi like Razer Core X but that had a daisy chain connector too - so - 
 * ATX PSU means silent operation is possible and will support Vega 64, and 
 * >= 80W power delivery, and
 * daisy chain,
then that should be more useful, shouldn't it?

If you know of any such boxes, or have any comments, please let me know, thanks!

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts


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cmm
 cmm
(@mois)
Trusted Member
Joined: 2 years ago
 

https://www.reddit.com/r/eGPU/comments/92mabq/is_intels_thunderbolt_3_dual_port_controllers/  here, a guy says the dual-port Thunderbolt 3 controller indeed has 22gbps shared for both ports. =(

More aspects when choosing box - PCIe vs eGPU: https://www.reddit.com/r/eGPU/comments/92ndul/do_egpu_boxes_no_daisychain_have_special_firmware/

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts


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joevt
(@joevt)
Noble Member
Joined: 2 years ago
 
Posted by: mois

Other TB3 peripherals should be connected to a separate TB3 connector on the laptop, so they get the 10gbps separate bandwidth that a dual-port TB3 controller exports, so in this model eGPU gets 22gbps and peripherals 10gbps. (High-end quad-core laptops such as Macbook Pro 15" has two TB3 connectors, so they have double what I just described, split over four TB3 connectors.)

I would say shared instead of split. Any Thunderbolt device in a chain can use 22 Gbps. 10 Gbps is for devices that are USB 3.1 gen 2, but you could have connected a Thunderbolt 3 device which can take more than that (up to 22 Gbps) or a USB 1.0 device that only takes 1.5 or 12 Mbps. Usually only one device is being used at a time, so a Thunderbolt 3 device could get a full 22 Gbps. If more than one device is being used, then they'll share the 22 Gbps (maybe equally, maybe not)

Devices are connected in a tree structure starting from the CPU. Various branches allow different bandwidths. Twigs of a branch do not need to have max bandwidths that add up to the bandwidth allowed by the branch. They could have bandwidths that exceed the branch (e.g. a PCIe x16 card in a x4 slot) but the bandwidth they use cannot exceed the bandwidth allowed by the branch.

I don't know how the devices are in your laptop. Here's an example:

- CPU (126 Gbps)
    - Thunderbolt 3 Controller 1 (31.5 Gbps)
        - Thunderbolt Port 1 (22 Gbps)
        	- eGPU (22 Gbps)
        		- eGPU second Thunderbolt 3 port (22 Gbps)
        - Thunderbolt Port 2 (22 Gbps)
    - Thunderbolt 3 Controller 2 (31.5 Gbps)
        - Thunderbolt Port 1 (22 Gbps)
        - Thunderbolt Port 2 (22 Gbps)
    - Other Devices
    - PCH (31.5 Gbps)
        - Other Devices

It may be that the 126 Gbps branch is used by a dGPU in the laptop. Therefore the Thunderbolt 3 and other devices would be connected to a PCH (31.5 Gbps).

Another possibility is that a dGPU has a 63 Gbps connection (PCIe 3.0 x8), allowing 63 Gbps for the other devices.

Posted by: mois

but the PSU is of the SFX kind and there are fewer options for those on the market, so I would be less sure that I can drive the Breakaway Box with a Vega 64 while fanless.

True. There are SFX up to 800W (not fanless) but they are of the SFX-L variety, where one dimension is up to 30mm longer than SFX, so you have to have the eGPU to make measurements and determine if they can fit.

Posted by: mois

(From talking to people, I understand that you should not daisy chain your eGPU, because the eGPU needs its 22gbps bandwidth already badly. Except for that however TB3 daisy chaining appears to work well.)

If you're not using the eGPU to power an internal display, then bandwidth is not a problem. People are using eGPU's with PCIe 2.0 x1 connections (4 Gbps). Look at crypto currency miners that use 1x to 16x risers that connect to a slot using a USB cable. For game performance, there are many benchmarks to be found for reduced bandwidth connections:
PCI Express vs. Thunderbolt - How much performance drop of your GPU you will have if you put it in eGPU
GeForce GTX 980 PCI-Express Scaling
AMD Radeon Fury X PCI-Express Scaling
NVIDIA GeForce GTX 1080 PCI-Express Scaling

There isn't a big drop until you get down to the 8 Gbps range. Even then, performance is still > 75%.

Posted by: mois

Also, I realize that there can be situations where a daisy chain connector *can't hurt*. Maybe there are some moments when you need to run two bus-powered Thunderbolt devices at the same time, and you have your eGPU connected to your laptop, and your laptop has only two TB3 ports.

I would like to have a second connector just for the option of using it. It practically comes for free on every Thunderbolt 3 controller (with a DisplayPort output too). The second Thunderbolt 3 port is the main reason for the existence of the Blackmagic eGPU (with the internal DisplayPort connections to the eGPU's GPU).

Posted by: mois

Therefore, if there was a chassi like Razer Core X but that had a daisy chain connector too ... If you know of any such boxes, or have any comments, please let me know

The eGPU.io Buyer's Guide will be updated when new eGPU's become available. Maybe the Blackmagic eGPU won't be a one off and we'll see more like that.

Posted by: mois

here, a guy says the dual-port Thunderbolt 3 controller indeed has 22gbps shared for both ports.

I won't believe that until I see benchmarks. The Thunderbolt3_TechBrief_FINAL.pdf document he refers to mentions 22 Gbps only in relation to a Thunderbolt 3 port, not a Thunderbolt 3 controller.

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case


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