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LuigiL
03-23-2018, 11:20 PM
My configuration:
Dell Latitude e7389
Dell Dock D6000
Dual Display - Dell U3417W Curved

I was really annoyed by poor performance of Dell D6000 , with continuous input lag and stutter.

Upgrading to 8.5 and activating the new encoder has improved performance hugely.
Moreover the CPU utilisation is now down, albeit GPU utilisation has gone up considerably.
I understand this is beta, and performance was not a focus, indeed there is still some noticeable lag and at time stutter, but I count on those going away when new encoder will be GA.

Good job !

AlbanRampon
04-06-2018, 03:44 PM
Thank you for the feedback Luigi,
Developers were delighted to read you, but a bit too shy to acknowledge.

You are totally correct, the number of images per second is low.
Reason is well understood and is because the first step was about changing all the plumbing and encoder to receive feedback on the concept.

Would you please be able to give me a few words on your use case?
The machine you have is recent, with most decent specifications. I would like to understand what type of applications are running and what is on the display when you experience the stutter, just to make sure we're not missing something important.

Kind regards,
Alban

LuigiL
04-07-2018, 12:46 AM
They deserve it.

I think part of the issue is I'm pushing the hardware to it's limit - the dual 34" are running at 3440x1440 each - and stacked vertically for an effective 3440x2880 screen size.

I'm mostly doing office-type work , large excel files, word documents, powerpoint and firefox or edge internet browsing.

No gaming or other drawing-intensive (CAD / Paint) activity.

The system just feel "heavy" , my impression is like the USB channel is saturated and is taxing the CPU to handle the traffic.

The D6000 is connected via USB-C on the charging port. I also connect keyboard, mouse, wireless headset and a webcam on the same dock. Network is wired and handled on the same dock too

OS is Windows 10 Insider Preview "slow ring" - currently on version 1803 build 17133.1

I'm constantly looking at task manager with "performance" pane open, and the GPU is often raising over 50% for "Windows Driver Foundation - User-mode Driver Framework"

I'm happy to assist if you want some sort of logging or recording or telemetry that might help you improve performances, to me there is clearly correlation between screen redraw and slow down of performances.

LuigiL
04-12-2018, 01:19 PM
Want to add an interesting finding.

I used the notebook with lid down, hooked into Dell D6000 connected to the two external screens.

The other day, for fun, I decided to try a 3 monitor configuration by opening the lid and having the notebook LCD screen be the 3rd screen.

Surprise, I started to feel the notebook less "sluggish" ... it felt snappier. and the GPU indicator in task manager looked less loaded too.

Eventually got annoyed by the set-up, so tried to keep lid open but disable screen extension. At first performances stayed the same. But eventually they degraded again.

Today I discovered overnight Windows had restarted, so thought of reactivating the 3rd screen to see ... and again a sense of performance improvement.

Is it possible that the onboard GPU is contributing to performance of the overall system, also the screen drawn by displaylink ?

Perhaps Windows does need a "true-GPU" driven screen to be active ? (note, the primary screen is always a displaylink connected one.)

Other thoughts ? I'm keeping the 3rd screen on for now, but would be better to be able to close the lid.

AlbanRampon
04-12-2018, 02:31 PM
Hello,

Very interesting findings indeed!

Our technology is not Graphics Processing Units (GPU), the chips don't compute graphics.
The operating systems will give the desktop composition work to the GPU. When pixels are computed, the OS hands them over to our driver which will encode them, ship them to the dock after USB encapsulation to be hardware decoded in the peripheral.

If I was to make an educated guess, I do not believe the fault is around Windows is here. I would place it on the graphics driver, but I prefer analysis to educated guesses...

There are several possibilities.
- One could be that the platform was *designed* to have performance throttled when the lid is closed. I've seen this in the past because of thermal constraints. You can detect a lid open with on-board display off, but it depends on system conception.
- What is also possible, most likely even, is that the graphics driver decides to go in lower performance mode when there's no direct display connected to save energy because they haven't thought about the notion of indirect displays which became a standard Windows feature in Windows 10 Anniversary Update (so about 2 years ago).
- Another possibility is an OS bug, but unlikely: Windows doesn't decide to shoot down GPU performance on its own. There was a bug around this 2 years ago in the OS, in a similar use case, but with extremely obvious 10-second pauses between updates, and it was fixed within the first month of discovery.

It is a bit more difficult to sense performance changes though, compared to it doesn't work at all.

As a first step to find where this issue lies, I would like to get the machine details from you so this can be assigned to a team to look at.
Would you please use the last link in my forum signature to generate logs and post System_Details.txt? You can remove the machine network name, and username logged in, but I'd really need the all CPU and GPU lines, at least. If you had a description of the application it's most visible on, that would be useful too so we don't spend too much time just reproducing this and focus on analysing it so this can then be routed to the rightful owner.

Kind regards,
Alban

LuigiL
04-12-2018, 09:15 PM
here you go with the logs.

It's very visible in firefox, browsing and writing this very forum for example you would see a "lag"

Excel and Word open at wide (3440 resolution) also show a similar behaviour.

I've run in both conditions.
3 displays (lid open and active)
2 displays (lid closed)

and can definitely see a difference in performance.

AlbanRampon
04-13-2018, 10:00 AM
Thank you very much Luigi.

I believe this is enough for engineering to start.
I have it queued in a team and will post here when I have either something to share or if we need more information from you.

Kind regards,
Alban

Ref 27660 - Max GPU seems throttled when no direct display present

AlbanRampon
05-01-2018, 11:47 AM
Hello,

The team hasn't been able to reproduce yet.
Recommendation is to clean up and reinstall as you've got mixed 8.3+8.5. I don't see why this would be the root cause as you seem to have had the issue before 8.3 but it's thankfully not too taxing.
Clean-up = http://support.displaylink.com/knowledgebase/articles/724494-cannot-upgrade-or-uninstall-displaylink-software
New version to install = http://www.displaylink.com/downloads/file?id=1138
Then, I can supply them with new logs.

Can you also confirm both displays are connected through DisplayPort?

Kind regards,
Alban