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What is required to power a external GPU with Intel's new thunderbolt 3 dock?

gonepostl 4,103 338 January 29, 2016 at 08:25 AM
Can't understand this at all. People say that usb type C will supply enough power for a r9 390, but how can that be when:

Usb type c can only supply a max of 3.0A or something like that. 3A at 12v is 36W. Maybe it will use a few of them or something. Or externally powered idk. Searched google with little results. Really excited about egpu's, please clear up my confusion on what I'm going to need to supply enough power to an external dock for a desktop gpu!



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USB 3 has multiple power delivery options. See
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Vague questions receive vague answers . . . . . .
Fairly certain that most external GPU enclosures will include a dedicated power supply and require an external power source. The Razer Core enclosure will have a 500W power supply according to the specs (though it only supports a max power delivery of 375W to the GPU) [1] and pictures of it clearly show a slot for a standard 3 prong power cord [2].

Also, the specs for the USB Power Delivery 2.0 protocol indicate a maximum delivery of 100W [3]. Despite the fact that the specs describe support for bidirectional delivery (ie. receiving and supplying power) from what I've seen this is currently thought of as a theoretical maximum due to the fact that full support of the USB PD 2.0 protocol is an option rather than a requirement for USB Type-C devices. Anandtech has a good explanation of the impact of this detail:
Quote :
With Type-C’s Power Deliver 2.0 specification allowing for chargers that can supply up to 100W of power, it will be possible (though optional) to use Thunderbolt 3 to deliver that same power, allowing for uses such as having a Thunderbolt dock or display charge a laptop over the single Thunderbolt cable (the one thing Apple’s Thunderbolt display can’t do today with Thunderbolt 2). That said, the USB power delivery standard is distinct from Thunderbolt’s bus power standard, so this doesn’t necessarily mean that all Thunderbolt hosts can provide 100W of power, or even any USB charging power for that matter. For standard bus-powered Thunderbolt devices, the Thunderbolt connection will now carry 15W of power, up from 10W for Thunderbolt 2. [4]
So even if Thunderbolt 3 took full advantage of USB Type-C's support for Power Delivery 2.0 (which it doesn't) and supported powering external devices at 100W (which it can't), it still wouldn't be able to drive the notoriously power-hungry 390.

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Last edited by chabreck January 29, 2016 at 10:27 AM
From what I've seen checking out the Thunderbolt, they ship with the power supply required.
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