What is the difference between PD-IN and upstream charging on a dock?

PD-IN is what the dock accepts from the wall charger. Upstream, sometimes called host charging or pass-through, is what it forwards to your laptop. The difference is what the dock keeps for its own ports and electronics. Anker's Nano USB-C Hub (8-in-1) lists a 100W max PD-IN and up to 85W passed to the host, so the gap is 15W.

How big a charger does my dock need?

At least the dock's PD-IN rating, and more if the dock has powered ports you actually use. A dock that accepts 100W paired with a 65W charger will not throttle gracefully in a predictable way; it will simply have less to allocate, and the laptop is usually last in line behind the ports. Match the charger to the PD-IN figure, then check the total your ports can draw.

Does a bigger charger charge my laptop faster through a dock?

Only up to the dock's upstream limit and your laptop's own limit, whichever is lower. Feeding a 300W charger into a dock that forwards 85W still gives the laptop 85W. The extra headroom does help the dock's other ports keep full speed while the laptop charges.

Why does a docked laptop still lose battery during heavy work?

Because a laptop under sustained load can draw more than the dock forwards. A machine that wants 100W on a native charger and receives 85W through a dock will run at a slow net discharge while rendering or compiling, then recover when the work stops. It is not a fault, it is a budget.

Do charging stations with AC outlets avoid the problem?

They sidestep it. A block such as the Anker Prime Charging Station (8-in-1, 240W) at $129.99 lets the laptop keep its own charger on an AC outlet while the USB ports handle phones and accessories, so no dock is dividing power at all. You still need a separate hub or dock for data and displays.

Your Dock Says 100W. Your Laptop Gets Less. Reading Host Charging Numbers

A hub rated 100W PD-IN does not deliver 100W to your laptop, because it keeps a slice for its own ports. Anker's 8-in-1 hub takes 100W in and passes 85W on. How to read PD-IN versus upstream charging, how big a charger each dock needs, and when the number stops mattering.

Published: September 7, 2026 Updated: September 7, 2026 GadgetHub Editorial

Disclosure: this article contains affiliate links (Amazon Associates and impact.com). We earn a commission if you buy through them, at no extra cost to you. Prices are the figures shown on anker.com and us.ugreen.com on September 7, 2026 and change often. Specifications are manufacturer-published. We have not tested this hardware ourselves.

Two numbers on a dock’s spec sheet look like the same number and are not. Getting them confused is why people buy a 100W charger, plug it into a 100W hub, and watch a laptop battery slowly drain during a busy afternoon.

PD-IN is what the dock takes from the wall. Upstream charging is what it gives your laptop. The gap is the dock’s own appetite.

The number that shows the gap

Anker publishes both figures for the Nano USB-C Hub (8-in-1, Dual Display), $35.99: a USB-C PD-IN rated at 100W max, and up to 85W passed through to the host. Fifteen watts stay in the hub to run two 10Gbps USB-A ports, a 10Gbps USB-C port, two HDMI outputs and an SD reader.

Fifteen watts is a reasonable overhead. The problem is not the overhead, it is planning around a number that was never the laptop’s number.

How the power actually gets divided

Work through it in the order the electricity does.

The charger’s total. A 65W brick has 65W to give, whatever it is plugged into.
What the dock accepts. If the dock’s PD-IN tops out at 100W, a 140W charger still only delivers 100W into it.
What the dock keeps. Its own controller, plus every bus-powered device on its ports. A portable SSD can draw several watts on its own; a bus-powered display or a phone charging on a downstream port takes much more.
What reaches the laptop. Whatever is left, capped by the dock’s published upstream figure.

The step people skip is number three. A hub with a phone charging on one of its ports is quietly spending your laptop’s budget.

Docks, charging blocks and what they publish

Product	Price (Sep 7, 2026)	Power figure to read
Anker Nano USB-C Hub (8-in-1, Dual Display)	$35.99	100W PD-IN, up to 85W to the host
Anker Nano Docking Station (13-in-1, Triple Display)	$149.99	Check the upstream figure, not the total
Anker Prime Charging Docking Station (14-in-1, Dual Display)	$269.99	160W class dock
Anker Prime DL7400 (14-in-1, DisplayLink)	$299.99	140W upstream charging
Anker Prime TB5 Docking Station (14-in-1, 8K)	$399.99	Thunderbolt 5 dock
UGREEN Revodok Pro 9-in-1 Multi-Display Dock	$169.99	Published PD-IN and pass-through differ
UGREEN Revodok Maxidok 10-in-1 Thunderbolt 5	$229.99	140W host charging class
Anker Prime Charging Station (8-in-1, 240W)	$129.99	240W across ports, AC outlets included

Notice that the DL7400, at $299.99, publishes 140W upstream as a headline feature. That is the number a 16-inch laptop owner should be shopping on, and it is a different figure from the port total that usually appears in the product name.

Check the Anker Prime DL7400 on Amazon

Sizing the charger without overspending

A workable rule: buy a charger at or slightly above the dock’s PD-IN rating, and add headroom equal to what your downstream ports will really draw.

A 100W PD-IN hub, laptop plus a mouse and keyboard: a 100W charger is enough. The Anker Charger (100W, 3 Ports, Smart Display) is $69.99, and the UGREEN Nexode 100W 4-Port Charger is $54.99.
The same hub plus a phone charging on it: step up. The Anker Prime Charger (200W, 6 Ports, GaN) is $69.99 on anker.com today, which is the same price as the 100W three-port unit. That kind of inversion is normal in both catalogues and worth checking before you buy the smaller one.
A 140W-upstream dock feeding a large laptop: you want a charger comfortably above 140W, and the dock’s own bundled supply if it ships with one.

Check the Anker Prime Charger 200W on Amazon

Check the UGREEN Nexode 100W on Amazon

The cable can cap everything

A charger and a dock that both support 140W will still deliver 60W over a cable that is only rated for 60W, silently. USB-C cables carry an E-marker chip that declares their current rating, and the negotiation respects the lowest link in the chain.

Anker’s Prime USB-C to USB-C Cable (240W) is $29.99 and UGREEN’s Uno USB-C to USB-C Cable 100W is $13.99, with a 100W retractable version at $15.99. Cheap enough that using an unknown cable to feed a $300 dock is a false economy. We went through the whole cable question in the three USB-C cables a desk needs, including the trap that a 240W power rating tells you nothing about data speed.

Check the UGREEN retractable 100W cable on UGREEN.com

The way out: stop making the dock do power at all

If the arithmetic annoys you, remove it. Keep the laptop on its own charger and let the dock handle only data and displays. A desktop block with real AC outlets makes that tidy rather than messy: the Anker Prime Charging Station (8-in-1, 240W) at $129.99 puts AC sockets and USB-C on the desktop, so the laptop’s own brick has somewhere to live that is not the floor.

Anker’s published allocation for that unit is unusually specific: each USB-C port can reach 140W max, two-, three- and four-port simultaneous output stays at 240W max, and five- or six-port output drops only to 237W max. Those are manufacturer figures rather than our measurements, but they are the most detailed allocation table either brand publishes, and we used the same table as the backbone of our desk charging station comparison.

Check the Anker Prime Charging Station 240W on Amazon

What we would do

Small laptop, light peripherals: a 100W charger into a 100W PD-IN hub, and accept 85W at the machine
Large laptop that works hard: a dock that publishes 140W upstream, fed by a charger above 140W, on a 240W-rated cable
Anyone tired of the arithmetic: laptop on its own charger, dock for data only, AC block on the desk
Everyone: check the upstream figure, not the number in the product name

Manufacturer allocation tables describe a ceiling, not a promise. What each device actually receives depends on what it requests, and two power-hungry devices asking at once will split the difference no matter what the table says.

Sources

All prices are store prices captured on September 7, 2026 and will change. Power figures are the manufacturers’ published specifications, not our measurements.

Frequently Asked Questions

Q: What is the difference between PD-IN and upstream charging on a dock?: A: PD-IN is what the dock accepts from the wall charger. Upstream, sometimes called host charging or pass-through, is what it forwards to your laptop. The difference is what the dock keeps for its own ports and electronics. Anker's Nano USB-C Hub (8-in-1) lists a 100W max PD-IN and up to 85W passed to the host, so the gap is 15W.
Q: How big a charger does my dock need?: A: At least the dock's PD-IN rating, and more if the dock has powered ports you actually use. A dock that accepts 100W paired with a 65W charger will not throttle gracefully in a predictable way; it will simply have less to allocate, and the laptop is usually last in line behind the ports. Match the charger to the PD-IN figure, then check the total your ports can draw.
Q: Does a bigger charger charge my laptop faster through a dock?: A: Only up to the dock's upstream limit and your laptop's own limit, whichever is lower. Feeding a 300W charger into a dock that forwards 85W still gives the laptop 85W. The extra headroom does help the dock's other ports keep full speed while the laptop charges.
Q: Why does a docked laptop still lose battery during heavy work?: A: Because a laptop under sustained load can draw more than the dock forwards. A machine that wants 100W on a native charger and receives 85W through a dock will run at a slow net discharge while rendering or compiling, then recover when the work stops. It is not a fault, it is a budget.
Q: Do charging stations with AC outlets avoid the problem?: A: They sidestep it. A block such as the Anker Prime Charging Station (8-in-1, 240W) at $129.99 lets the laptop keep its own charger on an AC outlet while the USB ports handle phones and accessories, so no dock is dividing power at all. You still need a separate hub or dock for data and displays.