Slow 2nd display

Hi @DavidEranen.
It seems to have the same behaviour.
Thanks.

@sach,

Is there also a slowdown if the model is just a simple box or sphere? How large is the model you are testing with?

-David

Just been doing a bit of a test using Task Manager to observe the resource use of CPU & GPU.

Some observations:

  1. Rhino 6 seems to clock up almost 100% of the Quadro when spinning the model versus around 60% in v5 for the same model.

  2. It’s independent of model size. Even smaller models can be an issue.

  3. I’ve just tested a small model and for some reason it’s even slower than the large model I’m working on…

@sach,

If you maximize the perspective viewport and switch to Wireframe or Shaded mode. Is it slow still when you move to other monitor? How about Rendered mode. Slow on other monitor?

If it’s only slow in Rendered mode, try disabling Skylight.

-David

@DavidEranen It’s seems to have erratic behaviour. The SL doesn’t seem to affect it. I’ve just toggled between maximized perspective viewport and 4 view and back again and it appears to have slowed down another 50%!!!

Unpredictable… Almost like it slows down the longer I work on the file…

@DavidEranen

Another observation. The bigger the viewport, the slower the model… I can have a small perspective viewport, and even zooming in close to more complex models is quick. The larger I make the view, the slower it gets…

@sach I sent you a private message.

@sach When you have time, could you time the following things:

All tests in fullscreen viewport, rendered mode without skylight shadows, and a simple test model:

Timing of TestMaxSpeed on:

  1. 4k screen in 4k resolution.
  2. 1200p screen while 4k screen is in 4k resolution.
  3. 4k screen in 1080p resolution.
  4. 1200p screen while 4k screen is in 1080p resolution.

Remember to log out and back in after changing the resolution of the 4k display.

Thanks
-David

I created this: https://mcneel.myjetbrains.com/youtrack/issue/RH-44796

Let’s just wait to see what else we can determine for now… It there is a problem in V6, and it can be fixed or tuned up, then we don’t want to lose the configuration that shows the problem.

David looks like he’s on the hunt for this one, so let’s just see what he comes up with.

-Jeff

For what it’s worth, I have run into some graphics issues, (in other applications, none in Rhino…yet), that were related to Dell’s “Switchable Graphics” setting, also referred to as “Optimus”. (pretty sure that’s what it’s called…edit: I think Optimus is an NVidia term).
It’s intention is for machines with 2 video cards, and it will “intelligently” switch depending on what the application needs. This is on machines with onboard intel cards, and a second “higher performance” card. It might be worth trying to disable “Switchable Graphics” in the bios and see what you get.
It seems that graphics issues, on dell laptops, with multiple cards, with external/second monitors connected via display ports…can sometimes get a little unruly. Maybe this is worth a read?

1 Like

@DavidEranen

Here are the results. The model is 100* 100mm2 (Polysurface) boxes.

  1. 4k screen in 4k resolution.
    2.61s
    38.33 FPS
    Maximized perspective VP at 3192*1469

  2. 1200p screen while 4k screen is in 4k resolution.
    5.19s
    19.28 FPS
    Maximized perspective VP at 4152*2309

  3. 4k screen in 1080p resolution.
    1.67s
    59.81 FPS
    Maximized perspective VP at 1500*715

  4. 1200p screen while 4k screen is in 1080p resolution.
    1.67s
    59.81
    Maximized perspective VP at 1980*1135

Thanks!
Sach

Hi @sach,

Interesting.

First point: It looks like the resolution rendered on the 1200p is 4x more pixels than it should be rendering. The display can’t even show that many pixels. This is probably due to the 4k monitor being the main display and the DPI is ~2x higher than the 1200p display.

Second point: It looks like V-Sync is enabled for Rhino. Can you go to NVIDIA settings and force-disable V-Sync for the Rhino application? Does this change anything? I’m thinking it might be interfering.

-David

@DavidEranen

I have disabled the vsync and it’s exactly the same.

Thanks,

Hi @DavidEranen
Any more progress with this?
Thanks!
Sach

Hi @sach,

Sorry, no progress. We have made a YouTrack item so we will eventually get to it, but I can’t say when.

@stevebaer and @jeff, I would appreciate if you could read through this thread (re-read for @jeff) and comment on what you think might be wrong or what we could test to find the root cause of the problem. Any suggestions are appreciated.

-David

I have seen that DPI mix-up here as well…It’s when you change the DPI scaling in Windows but don’t logout and back in (or reboot)… Windows just applies the scale factor across the board to whatever factor currently exists… I got my iMac (running Windows) using 10000x8000 at one point… Tearing off the viewport for a floating view crashed Rhino due the amount video memory it was trying to use…

If you’re getting resolutions reported that are greater than what your physical monitor is capable of, then you have a configuration error somewhere… I would start by setting Windows’ DPI setting to 100%…nothing more, nothing less… Logout and reboot… Then see what Rhino says your viewport resolution is.

-J

@jeff

We’re getting somewhere! Setting the scaling to 100% (down from the recommended 250%) makes Rhino respond as expected on the 2nd monitor.

Comparing the Rhino maximized VP, the approx. resolution:

4k main display, ~3500 px

1080 2nd display in ‘Extend’ mode, ~ 1600 px

But, now everything is tiny and illegible on the primary display!! Can you suggest how to address this?

Thanks,
Sach

@sach,

I’m not sure… The problem I reported above happens if you don’t reboot after changing the DPI setting… In other words, if you just go into Windows’ settings and change the DPI, close the settings dialog and just keep working… In fact, I think Windows even warns you with something like “Some applications will not work properly until you logout or reboot” (don’t remember the exact wording)…

So that being said… What happens if you set the DPI back to 250%, logout, reboot…and then try?

The thing to watch out for is what resolution is being reported in Rhino’s viewport tab…see pic.

image

If your view is maximized, and the Width and Height values seem (or are) larger than your physical screen capabilities, then something is wrong somewhere with the DPI settings. Rhino should never be using a resolution that is larger than what is possible…and the reason it even works is because when Rhino goes to move the frame buffer contents to the glass, the internal mechanism it uses to do so is scaling the results down to fit the “actual” viewport size…which may also be contributing to the slowdown.

  1. Determine what the maximum screen resolution is for your current config. Note: This is not necessarily the maximum resolution that your monitor is capable of… especially if you’re changing the DPI scale… It is the resolution you select in Windows’ Display settings…see pic.

So in the case above it would be 1920 x 1080…

  1. Now maximize Rhino, and then maxmize a viewport… and look to see what Rhino’s viewport tab reports as the Width and Height of the view… it should be close to (in this case) 1920x1080… it’s not going to be exact due to things like the command line, toolbars, and status bar all taking up screen real estate, but it should be close… What it should NOT be is something like 2x to 3x the size. If it is, then something is wrong.

So given all of that… I would first make sure that what you’re seeing from Rhino is all making sense in terms of resolutions and viewport sizes… Once you’re sure those are all correct, then I would start looking at performance… But until you can figure out why the correct resolutions aren’t being used (either a bug in Rhino or a Windows config problem), looking at performance issues will just result in false negatives (IMO).

-Jeff

Hi @jeff

Thanks for the update.

I’ve changed the main display back to 250% (the windows recommended setting), logged out and back in and we’re back to square one! So, the resolutions are: