What Windows laptop should I get in order to use dual external monitors?

September 3, 2021 9:26 AM

I need to get a new Windows-based laptop that will run two external monitors with different images on each of them. As in, I need to be able to see A on my laptop screen, B on the left monitor and C on the right monitor all at the same time. Can someone recommend a model or give me an idea of what specs to look for?

I currently have a Lenovo T470s -- the 3-monitor setup will work using a dongle that connects to a USB-C port on the laptop and has 2 HDMI ports for the 2 monitors. In the settings I can get both of the monitors to be "independent".

BUT ... sometimes it works and sometimes it doesn't. Sometimes the monitors just disconnect or stop showing the signal, sometimes it goes back and forth (on/off signal/no signal) quickly enough to be very annoying. This is not a monitor power problem -- they both stay powered on. It's the communication between the computer and the external monitors. I have tried 2 different dongles, both purchased new, different brands (Cable Creation and Anker) and have had the same problem.

Any ideas here? Do I need more processing power? A better graphics card? More RAM? The machine I have now is 3-4 years old, I'm doing Word/Excel/Teams/Zoom/etc. -- basic business stuff but no photoshop or gaming or video editing.

I need to know what exactly to look for so I can buy a new machine that will work consistently, because this is driving me CRAZY and I can't get my work done. I am also open to buying different cables/dongles if necessary.

(If you think this will work on a Mac, even better -- please tell me about it. But everyone so far has told me that I would have to buy an expensive Mac monitor to make it work and I want to keep using the monitors that I have.)

Thank you in advance for any advice or info!!

posted by mccxxiii to Computers & Internet (6 answers total)

You can find monitor that connects to USB-C. https://www.amazon.com/USB-C-Display/

So you only need ONE external monitor connected via built-in HDMI. Connect the other with USB-C. And finally, use the built-in monitor. VOILA: triple-screen

If you don't want to replace the monitor, you can try a plain USB-C to HDMI dongle.

I have a feeling the "double" adapter lost sync with the computer. A single should not have such a problem.
posted by kschang at 9:50 AM on September 3, 2021 [1 favorite]

Can't most docks do this? We have a variety of docks here from various laptops and they all have two video out ports. Then laptop connects to dock. (The point was supposed to be, this shouldn't need to be a laptop specific issue necessarily)
posted by getawaysticks at 9:52 AM on September 3, 2021 [2 favorites]

All of the current Intel Macs support three displays (for a laptop, this means 2 external plus the internal display.) The M1s do not. For a 4-port model this just requires appropriate adapters for two of the Thunderbolt ports. For a 2-port model it’s a bit more complex because you need to get a multiport adapter that can put the power-in and the monitor-out on the same physical connection. These are widely available, but often don’t support 4K resolution at 60Hz so if you need 4K you should choose carefully.

Most Intel Windows machines will too. Typically you would put one monitor onto a USBC port and the other onto an HDMI port.

You can also get a Displaylink adapter, which will work on just about any PC or Mac, and provide this functionality.
posted by doomsey at 9:53 AM on September 3, 2021 [2 favorites]

The laptop should be fine, however, not all 'dongles' are created equal. I would recommend a powered hub, such as this Thinkpad USB-C Dock. I use this same dock with my laptop in the same configuration that you are describing.
posted by wile e at 10:12 AM on September 3, 2021 [2 favorites]

Like wile e, I've had no problems running 2 monitors from a branded and powered Lenovo dock with a a ThinkPad L490, all at 1920x1080 resolution
posted by ambrosen at 11:12 AM on September 3, 2021

Corporate Thinkpad T480 user here. We use HP USB-C Thunderbolt docks at the office. The docks permenantly have 2 large screen monitors attached to them. The dock has a single USB-C cable that connects to the computer and provides it power and in turns allows the computer to drive the monitors. It works great and keeps all the crazy cables in their place.
posted by mmascolino at 1:38 PM on September 3, 2021 [1 favorite]