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rk25123

macrumors regular
Original poster
Aug 17, 2010
167
27
Hello,

Since Catalina disables the Displayport of the Nvidia GTX 680 Mac Edition, I bought an HDMI to Displayport adapter and a DVI to HDMI adapter for my second monitor, hoping to solve the problem. While the DVI to HDMI adapter works without problems, I'm not getting any image on the LED Cinema Display. Strange thing is that the monitor (which works normally with my MacBook Air) is recognized and listed in System Information: any ideas?

Many thanks!
 

rk25123

macrumors regular
Original poster
Aug 17, 2010
167
27
The GTX 680 has two DVI ports. You could try a Dual Link DVI to DisplayPort adapter: https://www.amazon.com/Gefen-GTV-DVIDL-2-MDP-Dual-Link-Converter/dp/B01LZT2Z15

What HDMI to DisplayPort Adapter did you get? Did you connect the USB for power?
Hi, thanks for the input! I bought this adapter (I did connect the USB):
To this, I connect the DisplayPort to Mini DisplayPort adapter (which always worked when used with the DisplayPort of the GTX 680). Maybe the problem is the double adapter? Someone in the comments said it worked for them with the same setup, though. I had found an HDMI to Mini DisplayPort adapter but it was almost double the price: maybe I should try with that one.
 
Last edited:

macguru9999

macrumors 6502a
Aug 9, 2006
645
243
Hello,

Since Catalina disables the Displayport of the Nvidia GTX 680 Mac Edition, I bought an HDMI to Displayport adapter and a DVI to HDMI adapter for my second monitor, hoping to solve the problem. While the DVI to HDMI adapter works without problems, I'm not getting any image on the LED Cinema Display. Strange thing is that the monitor (which works normally with my MacBook Air) is recognized and listed in System Information: any ideas?

Many thanks!
I have a couple of mac pro 5,1.... One of them has a mac edition firmware gtx680 card and normally i use the dvi port, but i tested the displayport running catalina (dosdude) and it runs just fine .... its not 'disabled'. I was just testing with a single monitor ,,,
 

joevt

Contributor
Jun 21, 2012
5,918
3,431
I have a couple of mac pro 5,1.... One of them has a mac edition firmware gtx680 card and normally i use the dvi port, but i tested the displayport running catalina (dosdude) and it runs just fine .... its not 'disabled'. I was just testing with a single monitor ,,,
I have an actual Mac Edition GTX 680 and the DisplayPort doesn't work in Catalina 10.15.7 (Dosdude patcher). It works in Mojave.
My card (EVGA Nvidia GTX 680 Mac Edition) has DVI-I, DVI-D, HDMI 1.4 and DisplayPort 1.2.
I wonder what the difference could be? Do all your ports work?
 

macguru9999

macrumors 6502a
Aug 9, 2006
645
243
I have an actual Mac Edition GTX 680 and the DisplayPort doesn't work in Catalina 10.15.7 (Dosdude patcher). It works in Mojave.
My card (EVGA Nvidia GTX 680 Mac Edition) has DVI-I, DVI-D, HDMI 1.4 and DisplayPort 1.2.
I wonder what the difference could be? Do all your ports work?
I dont have an 'original" card but i have flashed about ten of these identical cards over the years (2gb 680gtx ref cards) and as far as I knew you end up with an identical card to the "mac edition" since thats where the rom came from .... even if you were missing the driver you should get a signal via that port. when i just unplugged the hdmi cable and switched to the displayport i did not get a signal but when i rebooted it worked fine. As far as i remember all the ports work.
 

joevt

Contributor
Jun 21, 2012
5,918
3,431
I dont have an 'original" card but i have flashed about ten of these identical cards over the years (2gb 680gtx ref cards) and as far as I knew you end up with an identical card to the "mac edition" since thats where the rom came from .... even if you were missing the driver you should get a signal via that port. when i just unplugged the hdmi cable and switched to the displayport i did not get a signal but when i rebooted it worked fine. As far as i remember all the ports work.
I got DisplayPort working on my EVGA Nvidia GTX 680 Mac Edition in Catalina by modifying /System/Library/Extensions/AppleGraphicsControl.kext/Contents/PlugIns/AppleGraphicsDevicePolicy.kext/Contents/Info.plist
according to https://github.com/mayankk2308/purge-wrangler/issues/48
 

macronauts

macrumors newbie
Oct 6, 2021
11
0
I tried this for a GT630 I am having problems (with getting the displayport outputs) working on a cMP 4.1 flashed to 5.1 with Dosdude1's patched Catalina. The dvi port drives the 30" Cinema monitor just fine.

I added:

<key>Mac-fc200a2</key>
<string>none</string>
<key>Mac-F42C88C8</key>
<string>none</string>

The first made from system information id's, second from the thread for a gtx680, googling did not find another device ID for me to use. joevt was kind enough to point me at that thread.

No joy.

I have a few other cards to try once my mini 6 pin to 6 and 8 pin GPU power cables arrive.

Update: my GT720 did not need any power cables, and it has an HDMI port, that does work at up to 2k.
 
Last edited:

joevt

Contributor
Jun 21, 2012
5,918
3,431
I tried this for a GT630 I am having problems (with getting the displayport outputs) working on a cMP 4.1 flashed to 5.1 with Dosdude1's patched Catalina. The dvi port drives the 30" Cinema monitor just fine.

I added:

<key>Mac-fc200a2</key>
<string>none</string>
<key>Mac-F42C88C8</key>
<string>none</string>

The first made from system information id's, second from the thread for a gtx680, googling did not find another device ID for me to use. joevt was kind enough to point me at that thread.

No joy.

I have a few other cards to try once my mini 6 pin to 6 and 8 pin GPU power cables arrive.

Update: my GT720 did not need any power cables, and it has an HDMI port, that does work at up to 2k.
Why is Mac-fc200a2 lower case? Where did you get that number from? Here's a list of board IDs:
https://mrmacintosh.com/list-of-mac-boardid-deviceid-model-identifiers-machine-models/

The three numbers are:
Code:
				<key>Mac-F221BEC8</key>
				<string>none</string>
				<key>Mac-F221DCC8</key>
				<string>none</string>
				<key>Mac-F42C88C8</key>
				<string>none</string>

Mac-F221BEC8 = MacPro4,1 MacPro5,1
Mac-F221DCC8 = iMac10,1
Mac-F42C88C8 = MacPro3,1
 

macronauts

macrumors newbie
Oct 6, 2021
11
0
Thank you - that is an excellent link.

I made a guess that I needed a deviceid for the GPU, perhaps I mis-read the thread you sent me:

in https://forums.macrumors.com/thread...-display.2298246/?post=30204918#post-30204918

"I got DisplayPort working on my EVGA Nvidia GTX 680 Mac Edition in Catalina by modifying /System/Library/Extensions/AppleGraphicsControl.kext/Contents/PlugIns/AppleGraphicsDevicePolicy.kext/Contents/Info.plist
according to https://github.com/mayankk2308/purge-wrangler/issues/48"


As you can tell, I am new to mac's, in the past I mostly worked on Linux and Windows.

Due to my (mistaken) assumption, I tried to make a device id for the GPU by concatenating the deviceid and revision id from the hardware/graphics/displays in system information. I did not realize that upper/lower case mattered in hexadecimal numbers in a plist.

I will now remove the extra entries I added to the plist.
 

Runsc

macrumors newbie
Dec 4, 2019
28
3
I never got the DP working on my flashed Nvidia GTX 680 under OC Catalina. Since I updated to OC Bis Sur it works.
 

Runsc

macrumors newbie
Dec 4, 2019
28
3
I am running MyBootMgr 0.7.4b configured to load the default OC instance after a timeout. Both DP and HDMI ports are permanently connected.

When I select DP as active output on my LG 4K monitor and then power on my cMP, DP is detected as monitor 1 und HDMI as monitor 2 in Big Sur 11.6. I have no boot screen with DP. It activates later when loading Mac OS.

When I select HDMI as active output and then power on my cMP, I have a boot screen but only HDMI is detected as monitor in Big Sur.

My GPU is the EVGA standard model flashed with the Mac Edition FW. I did not configure anything special in MyBootMgr or Bid Sur. It just works.
 

Trungha

macrumors member
Sep 12, 2019
44
1
Viet Nam
I am running MyBootMgr 0.7.4b configured to load the default OC instance after a timeout. Both DP and HDMI ports are permanently connected.

When I select DP as active output on my LG 4K monitor and then power on my cMP, DP is detected as monitor 1 und HDMI as monitor 2 in Big Sur 11.6. I have no boot screen with DP. It activates later when loading Mac OS.

When I select HDMI as active output and then power on my cMP, I have a boot screen but only HDMI is detected as monitor in Big Sur.

My GPU is the EVGA standard model flashed with the Mac Edition FW. I did not configure anything special in MyBootMgr or Bid Sur. It just works.
Thank you for the useful information! I will try it later!
 

macronauts

macrumors newbie
Oct 6, 2021
11
0
I finally just received my two mini 6 pin to six pin cables!

I have to leave my lab soon, so I will try some other gpu's tomorrow.
 

macronauts

macrumors newbie
Oct 6, 2021
11
0
Just installed GTX660, much better than the GT720 it replaced. Haven went from 3.7fps (avg) to 20.2fps (avg)

Good news: 4k30 works from the hdmi output, ResXtreme is great.

Bad news: the mini display port output is inactive

More bad news: I can't find a flashable vbios for the card, so no boot picker (have to try OC again)

NVIDIA GeForce GTX 660:

Chipset Model: NVIDIA GeForce GTX 660
Type: GPU
Bus: PCIe
Slot: Slot-1
PCIe Lane Width: x16
VRAM (Total): 3 GB
Vendor: NVIDIA (0x10de)
Device ID: 0x1185
Revision ID: 0x00a2
ROM Revision: VBIOS 80.04.58.00.17
Metal: Supported, feature set macOS GPUFamily1 v4

Displays:

Cinema HD:

Display Type: LCD
Resolution: 2560 x 1600
UI Looks like: 2560 x 1600
Framebuffer Depth: 30-Bit Color (ARGB2101010)

DELL P2715Q:
Resolution: 3840 x 2160 (2160p/4K UHD 1 - Ultra High Definition)
UI Looks like: 3840 x 2160 @ 30 Hz
Framebuffer Depth: 24-Bit Color (ARGB8888)
 

OVERKILL338LM

macrumors member
Jan 8, 2022
61
23
Ontario, Canada
I am running MyBootMgr 0.7.4b configured to load the default OC instance after a timeout. Both DP and HDMI ports are permanently connected.

When I select DP as active output on my LG 4K monitor and then power on my cMP, DP is detected as monitor 1 und HDMI as monitor 2 in Big Sur 11.6. I have no boot screen with DP. It activates later when loading Mac OS.

When I select HDMI as active output and then power on my cMP, I have a boot screen but only HDMI is detected as monitor in Big Sur.

My GPU is the EVGA standard model flashed with the Mac Edition FW. I did not configure anything special in MyBootMgr or Bid Sur. It just works.
I just did a fresh install of Big Sur with OpenCore and was having the same problem as many in this thread. I have a flashed GTX 680 and was only getting output on my HDMI connected screen.

After reading your post, I disconnected the HDMI screen, rebooted, the DisplayPort screen came on, and once I logged in, I plugged back in the HDMI screen and both are now working.

A bit of a weird quirk, but thanks for detailing your experience, it made my troubleshooting a lot shorter.
 

Runsc

macrumors newbie
Dec 4, 2019
28
3
I heard it is not really an issue with a specific GPU but has something to do with the missing support of DP1.2 and HDMI 1.4 in the MP5,1 EFI firmware.

tsialex knows all the details about that problem.
 

OVERKILL338LM

macrumors member
Jan 8, 2022
61
23
Ontario, Canada
I just did a fresh install of Big Sur with OpenCore and was having the same problem as many in this thread. I have a flashed GTX 680 and was only getting output on my HDMI connected screen.

After reading your post, I disconnected the HDMI screen, rebooted, the DisplayPort screen came on, and once I logged in, I plugged back in the HDMI screen and both are now working.

A bit of a weird quirk, but thanks for detailing your experience, it made my troubleshooting a lot shorter.
So, some further discovery on this issue!

I went to replace my 27" Mac display with a larger 32" LG running the same resolution, 2560x1440, so I have two of those screens now. Well, the HDMI screen fired right up, but I could not get display on the one connected via DisplayPort. Hook up a lower res screen (1920x1080) through a DisplayPort to HDMI adapter cable, worked fine, tried that same cable with the new screen, wouldn't do 2560x1440.

Ended up using a Startech active Dual-Link DVI to DisplayPort adapter cable, and that works (though these cables are buggy) so I have both screens live now.

So, whatever "magic" is being done with the Mac firmware on these GTX680's, appears to make it expect a Thunderbolt screen on the DisplayPort connector; there has to be some sort of different handshake happening there, because it works fine with the Mac screen at the same resolution with nothing more than an adapter from DisplayPort to mini DisplayPort.
 
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