Mac Pro 5,1 and 4K Display Issues at Boot

LucMac

macrumors newbie
Original poster
Dec 17, 2014
18
4
GERMANY
Hi,

I recently replaced my old 27" Apple LED Cinema Display with an UHD LG 43UD79-B Monitor.
Thanks to SwitchResX, I'm super happy with the monitor, running in HiDPI @ 2160p over DP.

But I cannot start my Mac, when the Monitor ist turned on.
I can hear the Chime which repeats over and over again until I turn off the Mac by pressing the startbutton for 5 seconds.

I once managed to get a bootscreen in 1080p @ 30 Hz, by adjusting the bootscreen resolution in SwitchResX.
But that only worked once and never again.

My graphicscard is an AMD R9 280X (flashed).
My Mac Pro runs 10.14.1 with no other issues.
SIP is disabled and the Lilu/AppleHDA.kext patch is applied.

Thanks in advance,
LucMac :)
 
Last edited:

Montyboy

macrumors newbie
Feb 6, 2016
15
6
Germany
Hi,

I recently replaced my old 27" Apple LED Cinema Display with an UHD LG 43UD79-B Monitor.
Thanks to SwitchResX, I'm super happy with the monitor, running in HiDPI @ 2160p over DP.

But I cannot start my Mac, when the Monitor ist turned on.
I can hear the Chime which repeats over and over again until I turn off the Mac by pressing the startbutton for 5 seconds.

I once managed to get a bootscreen in 1080p @ 30 Hz, by adjusting the bootscreen resolution in SwitchResX.
But that only worked once and never again.

My graphicscard is an AMD R9 280X (flashed).
My Mac Pro runs 10.14.1 with no other issus.
SIP is disabled and the Lilu/AppleHDA.kext patch is applied.

Thanks in advance,
LucMac :)
I have the same monitor with no problems... Are you using the original display cable that came with the monitor.
 
  • Like
Reactions: LucMac

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
Hi,

I recently replaced my old 27" Apple LED Cinema Display with an UHD LG 43UD79-B Monitor.
Thanks to SwitchResX, I'm super happy with the monitor, running in HiDPI @ 2160p over DP.

But I cannot start my Mac, when the Monitor ist turned on.
I can hear the Chime which repeats over and over again until I turn off the Mac by pressing the startbutton for 5 seconds.

I once managed to get a bootscreen in 1080p @ 30 Hz, by adjusting the bootscreen resolution in SwitchResX.
But that only worked once and never again.

My graphicscard is an AMD R9 280X (flashed).
My Mac Pro runs 10.14.1 with no other issues.
SIP is disabled and the Lilu/AppleHDA.kext patch is applied.

Thanks in advance,
LucMac :)
Flashed 280X cannot boot with DP 1.2 connection. If you need boot screen, set the monitor to DP 1.1.
 
  • Like
Reactions: LucMac

bookemdano

macrumors 65816
Jul 29, 2011
1,211
701
Welcome to the hell I endured for a few months when I first got my cMP in 2016. None of the flashed Tahiti-era AMD cards will boot successfully when plugged into a 4K monitor via DP 1.2. As h9826790 said you can "solve" this by going into your monitor's menu and set the DP mode to 1.1. But the trade-off there is you'll only get a 30Hz refresh rate. You could also use the HDMI connector for your monitor if it has one. But you'll have the same 30Hz limitation.

Your only other options would be to unplug the monitor when booting (which is a major pain), or move your card's BIOS switch to the other position, which hopefully still has the non-flashed BIOS. This will allow booting but will not show any boot screens.

If you're not on Mojave then you could also buy one of the newer flashed Nvidia cards from MacVidCards. I ultimately went that method after fighting with my 7950 for a few months. The newer flashed Nvidia cards from MVC do have a DP1.2 compatible EFI driver so they show boot screens in 4K via DP 1.2. The downside to them (aside from the $$ to buy one) is that there are no drivers built into the OS, so with every OS release (even minor ones) you have to download a new version of the web driver from Nvidia. They have no drivers as of yet (or maybe ever) for Mojave so I really can't recommend that option at this point in time.
 
  • Like
Reactions: LucMac

LucMac

macrumors newbie
Original poster
Dec 17, 2014
18
4
GERMANY
I have the same monitor with no problems... Are you using the original display cable that came with the monitor.
I use the original LG display cable that came with the monitor. Are you using DP 1.1 or DP 1.2 and with which GPU?

Flashed 280X cannot boot with DP 1.2 connection. If you need boot screen, set the monitor to DP 1.1.
Can this be done with SwitchResX maybe? Because 30 Hz is no option for me. If only the Bootscreen is displayed in 30 Hz and then changes to 60 Hz after Boot, everything would be fine.

And why worked the 1080p@30Hz setting for only one time?
This would also be an acceptable solution for me.

Welcome to the hell I endured for a few months when I first got my cMP in 2016. None of the flashed Tahiti-era AMD cards will boot successfully when plugged into a 4K monitor via DP 1.2. As h9826790 said you can "solve" this by going into your monitor's menu and set the DP mode to 1.1. But the trade-off there is you'll only get a 30Hz refresh rate. You could also use the HDMI connector for your monitor if it has one. But you'll have the same 30Hz limitation.

Your only other options would be to unplug the monitor when booting (which is a major pain), or move your card's BIOS switch to the other position, which hopefully still has the non-flashed BIOS. This will allow booting but will not show any boot screens.

If you're not on Mojave then you could also buy one of the newer flashed Nvidia cards from MacVidCards. I ultimately went that method after fighting with my 7950 for a few months. The newer flashed Nvidia cards from MVC do have a DP1.2 compatible EFI driver so they show boot screens in 4K via DP 1.2. The downside to them (aside from the $$ to buy one) is that there are no drivers built into the OS, so with every OS release (even minor ones) you have to download a new version of the web driver from Nvidia. They have no drivers as of yet (or maybe ever) for Mojave so I really can't recommend that option at this point in time.
I'm on Mojave and don't want to downgrade anymore. It's a super stable and fast release for me (and maybe the last one for this old powerhouse :()

Setting the DP settings down to 1.1, if i need a bootscreen, is okay for me. Otherwise I'll let the monitor turned off, til the Mac has booted up.

Thank you guys for your replies! ;)
 

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
Can this be done with SwitchResX maybe? Because 30 Hz is no option for me. If only the Bootscreen is displayed in 30 Hz and then changes to 60 Hz after Boot, everything would be fine.
SwitchResX won't help.

You only need DP 1.1 during boot. Once boot screen shows up, you can switch it back to DP 1.2
 

UKenGB

macrumors member
Feb 21, 2010
81
8
Surrey, UK
Welcome to the hell I endured for a few months when I first got my cMP in 2016. None of the flashed Tahiti-era AMD cards will boot successfully when plugged into a 4K monitor via DP 1.2. As h9826790 said you can "solve" this by going into your monitor's menu and set the DP mode to 1.1. But the trade-off there is you'll only get a 30Hz refresh rate. You could also use the HDMI connector for your monitor if it has one. But you'll have the same 30Hz limitation.

Your only other options would be to unplug the monitor when booting (which is a major pain), or move your card's BIOS switch to the other position, which hopefully still has the non-flashed BIOS. This will allow booting but will not show any boot screens.

If you're not on Mojave then you could also buy one of the newer flashed Nvidia cards from MacVidCards. I ultimately went that method after fighting with my 7950 for a few months...
So are you saying my flashed HD7950 will not boot with a powered on monitor set to DP 1.2?

But if I leave the monitor off till after boot it will then work on DP 1.2, or I can switch monitor to DP 1.1 for boot, then to DP 1.2 once booted?

It's kinda workable, but far from ideal. Is this a problem just with a flashed HD7950? Or would a Mac Edition card also have the problem?

What other cards are there that don't need additional drivers, are Metal compatible, have Mac EFI so boot screens on all outputs and can do 4K with DP 1.2?
 

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
So are you saying my flashed HD7950 will not boot with a powered on monitor set to DP 1.2?

But if I leave the monitor off till after boot it will then work on DP 1.2, or I can switch monitor to DP 1.1 for boot, then to DP 1.2 once booted?
All correct.

It's kinda workable, but far from ideal. Is this a problem just with a flashed HD7950? Or would a Mac Edition card also have the problem?
All flashed 7xxx card using the Mac EFI that come from a genuine 7950 Mac Edition, so, won't make any difference.

What other cards are there that don't need additional drivers, are Metal compatible, have Mac EFI so boot screens on all outputs and can do 4K with DP 1.2?
Flashed Kepler cards.
 

bookemdano

macrumors 65816
Jul 29, 2011
1,211
701
Flashed Kepler cards.
Are you certain about that? I've never had a 680 myself but have come across posts here in the past that describe similar hangups when booting with a 4K monitor connected via DP 1.2. That's why I never went the 680 route after my troubles with the 7950--sounded like I'd be experiencing the same issue there. That's why I went with an MVC-flashed Maxwell card.
 

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
Are you certain about that? I've never had a 680 myself but have come across posts here in the past that describe similar hangups when booting with a 4K monitor connected via DP 1.2. That's why I never went the 680 route after my troubles with the 7950--sounded like I'd be experiencing the same issue there. That's why I went with an MVC-flashed Maxwell card.
Check MVC's blog, first page
 

UKenGB

macrumors member
Feb 21, 2010
81
8
Surrey, UK
Sorry, this is all deeper into graphics cards than I ever wanted to get. Kepler? Maxwell? I seem to recall MVC is a card supplier ? The others? Different GPU families?
 

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
Sorry, this is all deeper into graphics cards than I ever wanted to get. Kepler? Maxwell? I seem to recall MVC is a card supplier ? The others? Different GPU families?
Google can do better than us to answer your questions. Try google “Kepler GPU” and “Maxwell GPU”, then you will know everything you need to know.
 

LucMac

macrumors newbie
Original poster
Dec 17, 2014
18
4
GERMANY
The problem is his 280X is FLASHED, that Mac EFI is NOT compatible with DP 1.2 / 4K booting.

You are using a non flashed RX580 (and no Mac EFI available for flashing indeed), of course not affected.
OK, so I can easily stick with the RX580, because I can't see the Bootscreen anyways... (Only with switching to DP 1.1 during boot and then switching back again)

What's the difference between the Nitro+, Nitro lite and Pulse? Which one should I buy?
 

UKenGB

macrumors member
Feb 21, 2010
81
8
Surrey, UK
Google can do better than us to answer your questions. Try google “Kepler GPU” and “Maxwell GPU”, then you will know everything you need to know.
You told me everything I need to know about those designations, thanks.
 
Last edited:

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
OK, so I can easily stick with the RX580, because I can't see the Bootscreen anyways... (Only with switching to DP 1.1 during boot and then switching back again)

What's the difference between the Nitro+, Nitro lite and Pulse? Which one should I buy?
Little bit different setting / ports layout, etc. But mainly the cooler is different. If possible, stick to the PULSE should give you less trouble. That’s the Apple recommendation.

All of them can work, Nitro+ should give you better cooling, but the card will effectively occupy 3 slots.
 
  • Like
Reactions: LucMac

UKenGB

macrumors member
Feb 21, 2010
81
8
Surrey, UK
I notice the GTX 780 is Kepler based and looks a possible. So with a flashed GTX 780 in a cMP connected to a 4K monitor running DP 1.2 (60 Hz) it would be able to boot ok, i.e. full boot screen? And the DVI and HDMI ports are also usable and able to display boot/splash screens? Oh and it's a supported card so no drivers required?

Maybe this is a better bet than my HD7950.

Presumably the GTX Titan does all that the 780 can do, but faster and also needs no addn. drivers?
 

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
I notice the GTX 780 is Kepler based and looks a possible. So with a flashed GTX 780 in a cMP connected to a 4K monitor running DP 1.2 (60 Hz) it would be able to boot ok, i.e. full boot screen? And the DVI and HDMI ports are also usable and able to display boot/splash screens? Oh and it's a supported card so no drivers required?

Maybe this is a better bet than my HD7950.

Presumably the GTX Titan does all that the 780 can do, but faster and also needs no addn. drivers?
You have to check with MVC if all ports can display boot screen.

With DP 1.2 connection, it should display 1440p boot screen. And then further jump to 4k 60Hz only driver loaded.

HDMI port can’t do 4k 60Hz in any case.

Of course the card need driver, all GPU need driver, but just the driver is included in the OS for “supported” GPU.
 

UKenGB

macrumors member
Feb 21, 2010
81
8
Surrey, UK
You have to check with MVC if all ports can display boot screen.

With DP 1.2 connection, it should display 1440p boot screen. And then further jump to 4k 60Hz only driver loaded.

HDMI port can’t do 4k 60Hz in any case.

Of course the card need driver, all GPU need driver, but just the driver is included in the OS for “supported” GPU.
Yes I realise it needs a driver, but I meant no addn. driver required, over and above what is built-in to the OS.

So looks like the Kepler based 780 and Titan are the best Nvidia cards that can do 4K@60 via DP 1.2 (i.e. happily boot with just that one 4K monitor connected) yet require no additional driver. Yes?

Are there any AMD based cards that can do that? The 7xxx cards all use the same Mac EFI which doesn't support DP 1.2 booting, but can any later cards be flashed with a Mac EFI that does support booting at 4Kx60, i.e. via DP 1.2 (or above presumably).

I did notice the GTX 780 is PCIe 3. Would I be right in assuming it will work with PCIe 2 (e.g. in a cMP), just a bit slower?

Sorry to ask all these questions. GPUs and card are not something I usually bother much about - as long as it works. But getting Mojave on my cMP has forced me to have to look into it so I can obtain the functionality I need and it's something of a nightmare, with so many different possibilities and trying to determine what will or will not work and how well. MacOS 10.15 will be out before I've read enough to have a clear idea of what I need. Hence asking these questions as there are some here who have this information in their head and can easily answer, for which I thank them. :)
 

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
So looks like the Kepler based 780 and Titan are the best Nvidia cards that can do 4K@60 via DP 1.2 (i.e. happily boot with just that one 4K monitor connected) yet require no additional driver. Yes?
Correct

Are there any AMD based cards that can do that? The 7xxx cards all use the same Mac EFI which doesn't support DP 1.2 booting, but can any later cards be flashed with a Mac EFI that does support booting at 4Kx60, i.e. via DP 1.2 (or above presumably).
NO

I did notice the GTX 780 is PCIe 3. Would I be right in assuming it will work with PCIe 2 (e.g. in a cMP), just a bit slower?
Same as almost any other GPU. Even the Sapphire HD7950 Mac Edition card is a PCIe 3.0 card. With BootROM 138.0.0.0.0 or later, they can all run at PCIe 2.0 speed in any OS.
 

UKenGB

macrumors member
Feb 21, 2010
81
8
Surrey, UK
One more question I've not thought to ask. Can I assume that a 4K capable card would be able to output 3840 x 1600 (i.e. WQHD)?

I was just kinda thinking that if it can do 4K, then it can do this which is a bit less, but I guess that might be a bit optimistic. Again, hoping someone here knows.
 
Last edited:

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
One more question I've not thought to ask. Can I assume that a 4K capable card would be able to output 3840 x 1600 (i.e. WQHD)?

I was just kind thinking that if it can do 4K, then it can this which is a bit less, but I guess that might be a bit optimistic. Again, hoping someone here knows.
99% yes, if not, usually some software / cable, or even monitor setting issue, but not the card / GPU itself can't do it.
 

bookemdano

macrumors 65816
Jul 29, 2011
1,211
701
Check MVC's blog, first page
So you're referring to this quote?:

but frequently overlooked are the entry level Kepler cards. Specifically, the GT630 and GT640. These cards have boot screens on any port up to 2560x1600 and will do full 4K 60p once desktop is reached. and they DON'T REQUIRE Web Driver.
Interesting. Are these cards using the EFI that came from the 680 "Mac Edition" card, or is it a different one? Because other posts here have said that the 680 Mac Edition (and self-flashed 680s) will have the same hang at boot problem as the 7950 due to the EFI driver not being DP 1.2 compatible.

Before anyone sends MVC money to buy one, I would email him and ask him to clarify precisely that you can boot these cards with only a 4K DP 1.2 monitor connected, get boot screens at 2560x1600 on that monitor and then 3840x2160 once booted. It seems like that's what he's saying in his blog, but if so that's the first I've heard of it after almost three years of following this problem.

My understanding and experience with boot screens was that they are always displayed in the monitor's native resolution, whereas what MVC seems to be saying is that Kepler cards will downres for bootscreens. Would be a great solution if that's truly the case.
 

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
So you're referring to this quote?:



Interesting. Are these cards using the EFI that came from the 680 "Mac Edition" card, or is it a different one? Because other posts here have said that the 680 Mac Edition (and self-flashed 680s) will have the same hang at boot problem as the 7950 due to the EFI driver not being DP 1.2 compatible.

Before anyone sends MVC money to buy one, I would email him and ask him to clarify precisely that you can boot these cards with only a 4K DP 1.2 monitor connected, get boot screens at 2560x1600 on that monitor and then 3840x2160 once booted. It seems like that's what he's saying in his blog, but if so that's the first I've heard of it after almost three years of following this problem.

My understanding and experience with boot screens was that they are always displayed in the monitor's native resolution, whereas what MVC seems to be saying is that Kepler cards will downres for bootscreens. Would be a great solution if that's truly the case.
The boot screen definitely NOT always display at native resolution.

My CHG90 native resolution is 3840x1080. All GT120, HD7950, HD4870 not display the boot screen at its native resolution.

Anyway, yes, please consult him to confirm if that can work as what we believe.