USB 3.0 with 4K display works, but is sluggish


#1

I have Windows 10 RTM (Enterprise, 64-bit) with a USB 3.0 4K/HDMI Plugable adapter. I can run 3840x2160 at @ 24Hz, 25Hz, and 30Hz - and it seems the same for all, very sluggish.

What I mean is, if I drag a window, there is about a 1/2 second delay which just makes the UI “feel” slow and sluggish.

System has an AMD FX-8350 8-core CPU with 16GB of RAM. It looks like video rendering (DisplayLinkManager Application process) takes around 4-10% of the CPU.

Is this just “how it is” with this technology? Or, is there anything I can do to make the 4K “snappy” like the regular 1080 displays? Thanks!


#2

Hi Rob,

At UHD resolutions there can be a bit of additional input lag/latency, but the .5 second delay you’re describing sounds excessive.

A few different factors that could be in play here. A few quick questions/suggestions:
-Which model of display are you connecting to?

-Does your display support 2560x1440 input? If so, does that perform better? If it doesn’t support 1440P, how about 1920x1080 performance?

-Which model of graphics card/GPU is installed in your AMD system? Did you manually install drivers for your graphics card, or are the drivers that Win10 installed automatically being used?

Thanks!
Gary


#3

The display is a Sceptre U508CV-UMK

The available next resolution is 2048x1152 - nothing in-between. That and regular 1080 give ok response, but the screen is very blurry, like an analog signal. This lag is definitely most-noticable at the max resolution.

The traditional video card is a VisionTek ATI Radeon HD 5570 where I’m using 3 x DVI-D connections to 1920x1080 screens. And I’m just using what came with Windows 10, as that seems to work just fine. Should I install the specific drivers from the manufacturer?


#4

Hi Rob,

Appreciate the info on the Sceptre. Our Seiki TV for testing is similar - no available resolutions between 2048x1152 and 2160P.

We’ve had pretty decent results with the Windows 10 “in box” AMD drivers, so while I wouldn’t expect a substantial change with AMD’s updated drivers, it’s certainly worth trying.

Also, since you’re already pushing 3x1080P displays through the graphics card, I’d suggest disconnecting two of these DVI displays as a test scenario - curious if things run more smoothly with 1xDVI@1080P and 1xUSB@4k.

I’ll look forward to your test results on the above, and I’ll do some digging into any settings that may be relevant for the Sceptre.

Thanks!
Gary


#5

Gary,

Thanks for looking into this. With the other monitors disconnected, it’s still the same. I then installed the vendor drivers and I think(??) it may be a couple notches better. It’s difficult to tell, but it seems like there is less lag.

Primarily, I was just looking to see if there was some easy thing to do - like a registry entry, or turning down the color depth (which you can’t do in Windows 10?), etc. I just wanted to see if there were any shortcuts to get a snappy resolution. The vendor drivers seem to make a small difference.

Thanks much!

-Rob


#6

Hi Rob,

Glad to hear the updated AMD drivers seem to have helped a bit.

Not finding much noteworthy on this particular TV, spec wise. (Which is odd - there’s countless threads online for some of the other popular TVs that people use as monitors - Seiki, Changhong, etc - but next to nothing on this Sceptre which has way better specs.)

Ultimately I suspect there’s probably a combination of factors contributing to the less-than-optimal experience:
-Input lag: TVs generally have a much higher input lag than PC monitors. Usually not noticeable when watching movies, but definitely noticeable with PC input, especially in conjunction with a lower refresh rate.

-GPU horsepower: I’m wondering if a faster graphics card would behave better (since the DisplayLink chip offloads some of the graphics processing to the primary video card). When DisplayLink originally released the 4k-capable DL-5500 chipset, they were advising that the AMD 5xxx series of GPUs was the minimum recommended series of card. They’ve since updated their requirements to list the 7xxx as the minimum recommended spec.

Though of course if you were going to update the graphics card, it would probably make sense to simply get one that supports 4K out of the box. :slight_smile:

So given the above, it might make sense to return the USB graphics adapter and go with a replacement graphics card instead if the performance isn’t usable in the current state. If you wish to go this route, please send us an email to support@plugable.com and we can advise on the next steps for that.

Thanks!
Gary


#7

Gary,

After having used this for day with the new drivers - it does seem better. The lag definitely isn’t as noticeable. And I am a software developer where I have fairly static windows open - so any remaining lag issues aren’t really a problem. It’s not like I play games on it or anything.

So for me, yeah I will likely keep this setup - it’s working fine - and it’s rock-solid-stable. I haven’t had a single issue otherwise. Down the road I might upgrade the video card, but the for foreseeable future, this will be fine. This product does exactly what I was looking for in the short-term.

Thanks for the follow-up and the information, I appreciate it! I consider this issue closed.

-Rob


#8

Hi Rob,

Sounds good - glad to hear things are workable as-is.

Cheers,
Gary


#9