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Power Supply with Thunderbolt WD19TB
I have a 2-month old XPS 15 7590 (i9-9980) with NVIDIA GTX1650 (4 GB), 1TB SSD, 32 GB RAM, and Windows 10 Pro. I also ordered and just received a Thunderbolt WD19TB (130w). Do I still need to use my regular Dell power supply (barrel connector) while using the Thunderbolt? It is not clear to me whether I will need both power supplies or whether it is even advisable to use both at the same time. Normally I will use this laptop as a desktop, plugged in to AC power with several external hard drives.
-Robert
jphughan
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April 14th, 2020 10:00
@rray6 the WD19TB is only officially sold by Dell with a 180W power supply, which is capable of passing up to 130W through to the system if the system supports that, which the XPS 15 does. The regular WD19 (non-TB) can be ordered with either a 130W power supply (90W passthrough) or 180W power supply (130W passthrough). So when you say you have a WD19TB 130W, make sure that the 130W refers to the passthrough capacity by verifying that the sticker on the power adapter itself says 180W somewhere.
If you have a WD19 or WD19TB with a 180W power supply, then you do not need to keep the XPS 15's own power supply directly connected, because the XPS 15 is designed for a 130W power source. Dell actually stretched the industry-wide USB Power Delivery spec, which officially maxes out at 100W, in order to carry 130W over USB-C/TB3 specifically to support powering systems like the XPS 15 from some of their docking stations.
If on the other hand you have a 130W power supply, then that shouldn't have come with a WD19TB. But regardless of whether you have a WD19TB or a WD19 in that case, the 90W passthrough available from the dock wouldn't be enough to run the 130W XPS 15 optimally, so if you run off dock power, you might see things like slower battery charging and performance throttling. The only way to avoid that would be to keep the system's own power supply connected directly as well, in which case it will run from that instead. Or of course you could get a 180W power supply for the dock. Those can be ordered separately (any Dell 180W power supply will work), or of course you might want to return/exchange whatever you got if it was incorrect.
rray6
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April 14th, 2020 11:00
You are correct! I just checked and my WD19TB power supply says 180W. The description on the Dell accessory page says 130W power delivery which is what I read. Thanks for the clarification. You should write product descriptions for Dell. Thanks very much!
-Robert
jphughan
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April 14th, 2020 11:00
@rray6 thanks very much, and glad I could help! The "Power Delivery" spec refers to "USB Power Delivery to the attached system". And in fairness, I guess the amount of power the dock can provide to the attached system is more important to people than the amount of power the dock has to have feeding it in order to achieve that end result. It's pretty easy to see how much power your system requires (by checking its own power adapter), but the amount of power the dock needs in order to pass that through has changed. For example, the WD19TB's predecessor the TB16 used a 240W power supply in order to pass 180W through to the attached system.
R-dog
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April 1st, 2021 05:00
I have an XPS 9700 (i7-10875h 32mb ram and the RTX 2060mq). It is a 2021 build (so after power draw issues were supposedly sorted).
When a full load is applied running cinebench r15 the standard power adapter is pulling an consistent 132.2W at the wall and it is achieving a respectable score of 1808. No problems(except some thermal throttling).
When I use the WD19TB (with180w power brick) to supply power to the machine and run the same tests with identical power manager setting (optimized) and plugged into the same USB C port, The WD19TB's power supply only pulls 114.4W at the wall and the r15 scores drop accordingly to 1590. My power meter is quality and highly accurate and at no point have I seen the WD19TB pull more than 115w at the wall.
To me this doesn't appear as a fault with the dock as everything else is working fine.
Can you advise on how I can get it to supply its advertised 130w to my machine
Thanks in anticipation.