Any UI Lag with 2012 Retina Macbook Pro?

[MikhailT]

This is IMO not true: the GPU bandwidth even in the 2012 rMBP iGPU was greater than the requirements to scale to the required resolution. The problem was Apple's old graphics architecture and worst-in-class GPU drivers and OpenGL pipeline. Apple's OpenGL performance lags even open-source Linux driver implementations programmed by volunteers (see the numerous Phoronix benchmarks)!

The fact this is so much better in 10.11 should be significant evidence that the problem was with software not hardware! Apple dumps their terrible OpenGL implementation = most people saying how fast El Capitan feels on first generation rMBPs (which is what i have too).

Re: GPU bandwidth, there's enough bandwidth for the default Retina mode but bump it up at higher scaled resolutions, there's not enough to do everything in real time to avoid stuttering and lags. Anand did a technical analysis (a well respected technical analyst that Apple also hired) and reported that scaling itself was eating up a lot of the resources that even modern desktop GPU couldn't consume in real time. Rendering a static desktop is not the same as rendering a dynamic 60fps desktop with several animations effects and then downscaling it to fit the panel (we're talking about rendering 3840 x 2400 resolution at 60FPS and downscaling it in real time on a mobile chip). It's like running a 2012 vs 2015 games with several effects turned on the same GPU, there's only so much work it can do in a single frame and the more work it has to do, the more it struggles to keep the same FPS. A faster GPU would have more headroom for the 2015 game to do its stuff.

Compare a rMBP 2015 13" with iGPU vs rMBP 2012 with dGPU, you'll see more lags on the 13" than 15" running the same OS X at the higher resolutions (I did). I also turned off transparency and turned on dGPU all the time, this made a huge jump in consistency with the animations and such.

El Cap is much faster because Apple is doing less work (Mission Control is using less effects), optimized their under the hood frameworks and drivers like you said, and so on. Yes, this makes it seem like a software issue until you bumped up the resolutions and the problem is still there, only at a reduced level.

I still see a LOT of stuttering and lags in the highest scaled resolution on El Cap DB5 on rMBP '12 (clean install as well). I'm willing to bet that if Apple put a nVidia 980M chip in there, it'd almost eliminate the lags at the highest resolution.

Again, I'm not saying hardware is the sole cause. I'm saying the reason for the lags/stuttering is because Apple is doing a lot of stuff at the same time that its GPU can't run at 60FPS consistently. Unless Apple switches to Microsoft's scaling model or eliminate animation and effects in OS X, there is only so much they can do with the bandwidth the GPU has.

 

[nontroppo]

Again, I'm not saying hardware is the sole cause. I'm saying the reason for the lags/stuttering is because Apple is doing a lot of stuff at the same time that its GPU can't run at 60FPS consistently.

Computationally, scaling is cheap, and the fact there is little headroom even though the processing bandwidth is so high is because of all the inefficiencies in Apples compositing pipeline. The HD 4000 has a fill rate of 25.6GB/s which is 16x that required for the worst scaled resolution requiring 1.6GB/s fillrate. The headroom to perform other operations is there. Of course, I agree that throwing more hardware at this would trivially solve any problems, but I've run much more complex OpenGL workloads on the same GPUs running in Linux without any timing problems. Running that same workload in OS X and suddenly there are dropped frames all over the place (we do vision research and generate stimuli for presentation, using both a low-level KEXT and a hardware photodiode to test for frame consistency as it is critical for doing scientific research)...

Getting back to general use, I actually don't see much lag at all at my preferred resolution (HiDPI1920×1200), which should be the worst resolution overhead wise on 10.11, but then I saw little lag in 10.9 which got somewhat worse in 10.10 (but IMO was still very useable). I think 10.11 is smoother than 10.9, but it is incredibly hard to do A/B testing from memory, thus all the placebo "snappier" effects that get reported on these forums!!!

 

[phero]

What part does edram play in all this?

 

[Valkyre]

Can someone film a 2012 rmbp 15" UI performance test with an external camera and not via quicktime, to get more accurate representation of how smooth the UI is in El Capitan?

Resizing windows, opening and closing mission control, moving windows around and switching between desktops I think would be enough to get a fair idea.

Would appreciate if someone went through all this trouble.

 

[kwokaaron]

This is IMO not true: the GPU bandwidth even in the 2012 rMBP iGPU was greater than the requirements to scale to the required resolution. The problem was Apple's old graphics architecture and worst-in-class GPU drivers and OpenGL pipeline. Apple's OpenGL performance lags even open-source Linux driver implementations programmed by volunteers (see the numerous Phoronix benchmarks)!

The fact this is so much better in 10.11 should be significant evidence that the problem was with software not hardware! Apple dumps their terrible OpenGL implementation = most people saying how fast El Capitan feels on first generation rMBPs (which is what i have too).

Agreed. We're talking 2D desktop compositing here guys, not 3D graphics/rendering. The HD 4000 is more than capable hardware-wise to do these resolution scaling.

On another note, nontroppo, is the performance much better than Mavericks? From my experience, Mavericks is performs much better than Yosemite so I would be interested to know if the performance is better than even Mavericks as well.

What part does edram play in all this?

Not much really. eDRAM was implemented to reduce the memory bandwidth problem iGPUs often have, especially with games. It would have minimal, if any, impact on desktop compositing since the 'lag' that people experience is more related with software implementation/optimisation.

 

[phero]

Not much really. eDRAM was implemented to reduce the memory bandwidth problem iGPUs often have, especially with games. It would have minimal, if any, impact on desktop compositing since the 'lag' that people experience is more related with software implementation/optimisation.

Still, when comparing a 13" rMBP with Iris 6100 graphics to a 15" rMBP with Iris Pro 5200 graphics, it's quite clear that the latter handles desktop UI animations at a much higher average framerate than the former (in Yosemite). I'm thinking about mission control animations with lots of windows open, using multiple monitors, or using scaled resolutions.

In El Cap the 13" performs a LOT better (the 15" performs better aswel, but this is less noticeable because it already performs quite good in Yosemite). However, even in El Cap, there is still a difference in UI performance between the 13" and 15" rMBP's.

 

[jffluis]

Can someone film a 2012 rmbp 15" UI performance test with an external camera and not via quicktime, to get more accurate representation of how smooth the UI is in El Capitan?

Resizing windows, opening and closing mission control, moving windows around and switching between desktops I think would be enough to get a fair idea.

Would appreciate if someone went through all this trouble.

Here's a video that I made in a hurry. It is not perfect but I think that it can do the job for you

 

[phero]

Here's a video that I made in a hurry. It is not perfect but I think that it can do the job for you

Great vid. Any idea if that was with the HD4000 or 650m?

 

[jffluis]

Has you can see in the video gfxCardStatus on the menu bar always has de i so I was always using HD4000.

 

[Valkyre]

Here's a video that I made in a hurry. It is not perfect but I think that it can do the job for you

Now thats what I am talking about! Thank you so much! el Capitan seems to run beautifully in our machine! And to think its with intergrated gpu! Amazing. Thank you again for being so helpful, you just helped me decide to upgrade from Mavericks to El Capitan!

 

[phero]

Has you can see in the video gfxCardStatus on the menu bar always has de i so I was always using HD4000.

Awesome! Any chance you could check out if and how performance is affected when an external display is connected (on the HD4000)?

 

[Skika]

Awesome! Any chance you could check out if and how performance is affected when an external display is connected (on the HD4000)?

I dont think its possible to connect an external display and run iGraphics on models with dGPU.