TB16 180W vs 240w? XPS 9550

Which version do we need if I have the XPS 9550 laptop? I noticed a big difference in price right now, where one is on sale for $233 CDN and the other is $299.

Any ideas/suggestions? I believe the XPS 9550 requires 240w but I've been using the WD15 dock and don't seem of had any issues powering devices presumably because aside from ethernet and an external monitor, don't have a lot connected to it.

 

TB15 dock is just fine until you get 4k display...
Unfortunately it can run it only 4k@30Hz while TB16 run 4k@60Hz ...
There are no other major difference for XPS 15 9550,9560 users ... Actually 4k@30Hz - that's buy stopper for me ... picture is a bit laggy at this refresh rate.

 

I just bought a used 180w TB16 and set it up today. Seems to be working fine as far as I can tell based on one day's worth of experience.

 

Do you have it connected to a 4k monitor at 60Hz? Any warnings when you boot up saying your dock is underpowered for that laptop?

 

I have a QHD monitor (2160 x 1440) connected to the dock through mini-DP and it works fine. I don't see how 4k would make any difference, it's not like the dock is powering the monitor but maybe I'm missing something?

I don't see any warnings when the laptop boots, however I'm running Linux so your mileage may vary.

 

Don't know if relevant, but I have an XPS connected to a LG 38UC99, which powers the Notebook by USB-C. It's rated for just 60W, works fine. Just a warnung at boot, which can be turned off.

 

So do you also have problems with a very irritating fan in the TB16?

 

Isn't the wattage referring to the power supply, these docks are also meant for the 17" Precisions which may require 240W of power to perform adequately, the XPS 15 definitely does not, 180W should be more than enough to supply power to the laptop and the dock. Remember that peripherals like keyboards and mice don't require that much power and would be served fine by the laptop's adapter anyways and monitors, etc. will have their own power supplies because their interfaces aren't meant to carry power over.

 

Works, but how fine? The 9550/9560 can happily draw 130W under load. So I assume 180W is enough.
I've got the Dell 45W AC adapter connected right now and it works, but the CPU performance is restricted like on battery (may rise to max clock under prolonged CPU load, drawing power from the battery). The GPU performance is even more restricted than on battery.