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Remove 165 MHz pixel clock limit; 4K over HDMI; overclocking

T

Tom the MacUser

macrumors member
Original poster
Mar 26, 2013
31
1
I previously mentioned this patch on the forum, but since I just made it public it is time to make a separate thread about it.

Who is this for?

1) You want to overclock your display
2) You want to drive a 4K display/projector from your Mac

***

I just added 10.8.5 support and I published my work on Google Code.

Documentation and download links are here:

http://code.google.com/p/mac-pixel-clock-patch/wiki/Documentation

Let me know if it does work or does not work for you.

Also let me know if your OS X version or video card is not supported - I might be able to add it in. AMD/ATI video cards support is likely possible, I need testers!

Cheers!
 
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Ursadorable said:
Didn't they JUST come out with HDMI 2.0 standards last week to support 4K displays over HDMI?
Click to expand...

Yes, HDMI 2.0 with 4K 60fps support was just announced, and the previous HDMI 1.4 already supported 4K 30fps.

But that did not do any good to OS X users, because the OS X driver prevents using the high resolutions or refresh rates HDMI 1.4 made possible. The OPs patch removes this limitation. It's explained in the linked documentation.

Oh, and thank you OP :)
 
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Great! I just got a new rmbp and was thinking about patching it earlier today. I can also test w/ my iMac (6970) if you need - I accidentally bought a passive mdp ->hdmi 1.4 adapter, and it's locked to 165MHz also. Any idea if we're going to need to patch 10.9 as well?

BTW: Has anyone managed to drive any 4k display >30Hz? I was hoping I could take my Seiki to 35-40, but I can't seem to lock even at 31Hz....
 
Working . . . but chrome isn't always happy

I'm on a RMBP (10.8.5) connected to a Sieki 39" display directly via HDMI. Seems to be working, I'm at 3840x2160@30HZ. Main challenge I'm having is with Shockwave in Chrome: frequent plug-in crashes and very slow loading pages (if they ever load at all). This only occurs with chrome on the large screen and not when disconnected from it. I'm unsure if this is an issue with the video driver (or if this is even the correct place to post this finding). Anybody else seeing this? Also - selecting Turn Video Mirroring On in SwitchResX causes both screens to turn blue and the system becomes unresponsive. Again, not sure if this is a SwitchResX issue or a driver problem.

Thanks!
 
Timings

To add a little more context to my post above, I performed a startup test with Chrome on the internal display with the large display unplugged and then a second test with Chrome on the large display. Results are extremely different, something is definitely wrong with rendering to the large display.

Chrome startup with 5 windows and 39 tabs open:

Internal Display: 33.5 seconds
External Large Display: 6 minutes and still trying to load (with a number of shockwave flash plug-in not responding messages).
 
I've noticed on my rMBP that the discrete gpu (GT650) is always used when I hook up the Seiki, but when the display connected the system can use the Intel integrated video. Perhaps its not at all related to the large display, but instead the driver. (I don't use chrome, and specifically avoided installing flash on my systems, so can't test on my setup)

I would try forcing the gpu to discrete and see what happens. This utility is fairly convenient for controlling, and it' will also tell you when things switch over -- helped me realize that one particular app was powering up the discrete GPU and causing my battery to drain faister.

nice http://gfx.io
 
omvs said:
I've noticed on my rMBP that the discrete gpu (GT650) is always used when I hook up the Seiki, but when the display connected the system can use the Intel integrated video.
Click to expand...
The HDMI/TB outputs on the 15" rMBP seem to be physically connected to dGPU (nVidia) only, so no way to get iGPU picture on external display.
 
Furmac said:
Yes, when plugged into the Sieki, it seems only the NVidia card is active.
Click to expand...

Yeah, was suggesting forcing to NVidia, and running without the Seiki connected -- see if chrome has problems on the internal display -- if so, it must be a issue with the video drivers for nv.
 
I see. Just performed this test using the NVidia with the internal display. The resolution is currently set at 1680x1050.

40 tabs in 5 windows loaded in: 39.5 seconds

Interestingly, setting the resolution to 3840x2400 opens the same set of windows in about 35 seconds.

Loading on the external display still takes over six minutes . . .?
 
omvs said:
Any idea if we're going to need to patch 10.9 as well?
Click to expand...
The answer seems to be no. Mavericks supports 4K on my TV out of the box, but I can no longer use HiDPI modes. According to https://forums.macrumors.com/posts/17832271/, this seems to be intentional.

omvs said:
BTW: Has anyone managed to drive any 4k display >30Hz? I was hoping I could take my Seiki to 35-40, but I can't seem to lock even at 31Hz....
Click to expand...
Some people managed to overclock Chinese-only Skyworth 39E780U to 38 Hz. For my 50" Seiki 4K TV the max seems to be 31 Hz.

----------
Furmac said:
I see. Just performed this test using the NVidia with the internal display. The resolution is currently set at 1680x1050.

40 tabs in 5 windows loaded in: 39.5 seconds

Interestingly, setting the resolution to 3840x2400 opens the same set of windows in about 35 seconds.

Loading on the external display still takes over six minutes . . .?
Click to expand...
I have similar performance issues with Chrome on my IBM T221 4K monitor - running at 3840x2400 @ 31 Hz - 1920x1200 HiDPI. Firefox and Safari work great, I recommend using one of them instead.
 
Tom the MacUser said:
The answer seems to be no. Mavericks supports 4K on my TV out of the box, but I can no longer use HiDPI modes. According to https://forums.macrumors.com/posts/17832271/, this seems to be intentional.


Some people managed to overclock Chinese-only Skyworth 39E780U to 38 Hz. For my 50" Seiki 4K TV the max seems to be 31 Hz.

----------


I have similar performance issues with Chrome on my IBM T221 4K monitor - running at 3840x2400 @ 31 Hz - 1920x1200 HiDPI. Firefox and Safari work great, I recommend using one of them instead.
Click to expand...
WARNING:

If you currently use 1920x1080 HiDPI on your 4K TV on Lion/Mountain Lion, you may not be able to use HiDPI on your external monitor/TV once you upgrade to Mavericks. 3840x2160 standard DPI should work.

At this time I don't know how to enable HiDPI on an external display in Mavericks. If anyone finds out, please let me know.

----------
rabidz7 said:
I can test ATI gfx. Me has a 7970 and 6770M.
Click to expand...
Are you still on Mountain Lion? Please PM me or email me and I'll send you a new experimental version to test out.
 
pixel clock on 10.9?

Tom, I am running 10.9 and I see the same problem you describe with the pixel clock -- resolutions calling for a pixel clock higher than 165 do not work with the standard HDMI adapter. The Accell adapter is currently out of stock due to popular demand.

Are you planning an upgrade to your patch kit to remove the pixel clock limitation from 10.9 also?

Thanks for your help!
 
snowuser said:
Tom, I am running 10.9 and I see the same problem you describe with the pixel clock -- resolutions calling for a pixel clock higher than 165 do not work with the standard HDMI adapter. The Accell adapter is currently out of stock due to popular demand.

Are you planning an upgrade to your patch kit to remove the pixel clock limitation from 10.9 also?

Thanks for your help!
Click to expand...

Same issue with no pixel clock speed than 165 on Mavericks over HDMI. Early 2013 15 inch rMBP. Would love to see the patch upgraded for this. Thanks.
 
Tom the MacUser said:
WARNING:

If you currently use 1920x1080 HiDPI on your 4K TV on Lion/Mountain Lion, you may not be able to use HiDPI on your external monitor/TV once you upgrade to Mavericks. 3840x2160 standard DPI should work.

At this time I don't know how to enable HiDPI on an external display in Mavericks. If anyone finds out, please let me know.
.
Click to expand...


HiDPI is nice but even with SwitchResX you can make your own HiDPI presets, your just lucky if they pop up...on my Samsung LED I get 960x540p HiDPI options, and on my old CRT I get 640x480 HiDPI options even! But you can't create them...I'd love to create some custom HiDPI options for external displays as well as the internal...sounds petty but running 2160x1440 looks perfect I just can't get it to view properly on my rMBP's display.
 
Tom the MacUser said:
Also let me know if your OS X version or video card is not supported - I might be able to add it in. AMD/ATI video cards support is likely possible, I need testers!
Click to expand...

I have no problems with command line and I can test any OS version (10.6.8 up through 10.9) with Radeon 6630M.

On a side note, would this patch be able to help Mac users with single-link DVI output? For instance, to enable 3840x2400 @ 17Hz, 3840x2160 @ 18Hz, or at least 2560x1600 @ 30Hz output from a GeForce 9400M?
 
I have a late 2011 Macbook Pro with Radeon Card

I could also do the Test, i even could help you when you explain how you started.

I also have a 4k Display to test.
 
I found the same hex code string in 10.9 that gets replaced- so I gave the script a shot but that didn't seem to do anything (although luckily it still booted).

The original person who found the way to hack the nvidia drivers, do they have any documentation on how they did it?
 
Original and patched files

Hey all, I'm trying to look into patches for Mavericks. Is there anyone who has copies of both original unpatched and patched versions of both IOKit and the NvidiaHAL kext? I'd like to investigate how the patch works but I need both of those.

Thanks,
Doug
 
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