My 27" LG 4k display works fine on old 2013 Mac Pro using DisplayPort but doesn't on new Mac Pro 2019. Just shoes black screen. It does work on HDMI, but not what I'm wanting.
Using a USB-C to Mini DisplayPort adaptor.
Any ideas?
You generally cannot "stack" adapters, with very few exceptions.
Cable-Matters is a respected brand.
Those HDMI cables are rated for "4K", which is good.
If you have DisplayPort family input on your Display, using that provides higher resolutions, higher refresh rates, and cooler operation, because DisplayPort drops the "heartbeat" refresh, where ALL display data are re-sent every 60th second, changed or not. That is crucial for CRT displays, but just a waste of energy if your display can accept DisplayPort family.
You generally cannot "stack" adapters, with very few exceptions.
Cable-Matters is a respected brand.
Those HDMI cables are rated for "4K", which is good.
If you have DisplayPort family input on your Display, using that provides higher resolutions, higher refresh rates, and cooler operation, because DisplayPort drops the "heartbeat" refresh, where ALL display data are re-sent every 60th second, changed or not. That is crucial for CRT displays, but just a waste of energy if your display can accept DisplayPort family.
Note: This adapter does not support DisplayPort displays like the Apple LED Cinema Display or third-party DisplayPort and Mini DisplayPort displays. For more information, visit the Apple Support page for the Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter.
What can I use instead?
Monoprice Select Series USB-C to Mini DisplayPort Adapter -- Product # 24273 -- $23.39
https://www.monoprice.com/product?p_id=24273
the above is for a device with CAPTIVE Mini DisplayPort cable. There is a slightly cheaper model that is adapter/cable in one
Monoprice USB Type-C to Mini DisplayPort 3.1 Cable - 5Gbps, Active, 4K@60Hz, Black, 3ft -Product # 24446 - $19.59
Thank you. Earlier today I ordered 2 USB-C to DisplayPort cables - will these work, too? (And thank you for your help!)
When Apple adaptors don't work on Macs it always confuses me.
https://www.amazon.com/gp/product/B06XTZZYKX/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
My LG monitors have DisplayPort (the full size) so I won't be stacking adaptors. Fingers crossed this gives me the higher refresh rate.
I swear I can see the lack of refresh in the mouse cursor but maybe I'm imagining it. ;-)
Thanks for your help!
Cursor lag is (counter-intuitively) most often caused by something hogging the CPU, allowing no free cycles for the mouse-position refresh.
Human Threshold of Perception is around 1/6 second.
Display Refresh rate should be at least 1/30th second
2019 Mac Pro so (hopefully) it's not the processor, but it's pretty subtle - just a slight "graininess" as I move the cursor around the screen. I've noticed this before on HDMI.
I'll report back after getting back on DisplayPort. Like I said, it's subtle.
Final Answer!
#1. Apple USB-C to Thunderbolt 2 adaptor does NOT support DisplayPort monitors.
#2. The top USB-C ports (as well as the 2 on the back) on the 2019 Mac Pro WILL drive 4k monitors through DisplayPort.
That is all.
Checking in late to the conversation. I have a 27 inch Apple LED Cinema Display. Would I utilize your first option (Monoprice Select Series USB-C to Mini DisplayPort Adapter -- Product # 24273) for connecting it to the 2019 Mac Pro? Thanks!
what make&model Mini DisplayPort Adapter?
Is it rated for "4K" ??
It's an Apple adaptor, Model A1790.
What would you say, in summary, is the most surprising and/or vexing subtle issue you encountered, to pass along to "the next guy" who finds your post by searching?
The Apple USB-c to Thunderbolt 2 adaptor cable doesn't work on DisplayPort monitors. ;-)
yes, exactly.
Mac Pro 2019 - LG Display not working with DisplayPort
