New 2012 iMac as external display for PC

[vooblu]

I tested my iMac last night with a macbook pro and it went into target display mode without any problems. Luckily for me, that means my mac and thunderbolt cable are working correctly. It's either the PC which doesn't realize the mac is a monitor, or it's the mac which doesn't realize the PC is capable of outputting video over thunderbolt.

When connected to the PC, the "Thunderbolt" category in System Information on the iMac says "No device connected" for both ports, so that's one thing which stands out as an issue.

I've gone through the BIOS and have set iGFX as default, and enabled Internal Graphics. It can output to other monitors using the thunderbolt port and a mini dp cable, but iMac's obviously require the TB cable. I have found no settings to "send video output through thunderbolt". I would assume it's automatic and doesn't need any configuration.

 

[spazzwig]

I really hope to see a solution come up for this. I don't strictly need to update my PC, but it's old enough that I'm willing to if the iMac can work as an auxiliary display for it.

vooblu, earlier in the thread the possibility was raised that this will only work with Windows 8 (was no luck for hallee, but you're running a later series of graphics, you never know)... have you considered exploring that avenue? Perhaps Windows 8 drivers will allow OS X to recognize it as a connected device.

Would be nice if one of the review/testing sites that have a surplus of recent hardware would do some testing on this (i7-3770, various TB motherboards, Win 7/8, etc).

 

[2Turbo]

Dang, was hoping this might work...

 

[vooblu]

vooblu, earlier in the thread the possibility was raised that this will only work with Windows 8 (was no luck for hallee, but you're running a later series of graphics, you never know)... have you considered exploring that avenue? Perhaps Windows 8 drivers will allow OS X to recognize it as a connected device.

I think it may just be my motherboard model. I've seen a few people try with the same one as me (Z77X-UP4 TH) and none have been successful. Video does go through thunderbolt port since it works with the thunderbolt display - but when it's connected to the iMac, the iMac doesn't recognise the video - apparently.

I have all of the equipment for it to work, so if anyone has suggestions (apart from upgrading to Windows 8, I don't plan on doing that just yet), let me know and I'll give it a try.

 

[Mac32]

I think it may just be my motherboard model. I've seen a few people try with the same one as me (Z77X-UP4 TH) and none have been successful. Video does go through thunderbolt port since it works with the thunderbolt display - but when it's connected to the iMac, the iMac doesn't recognise the video - apparently.

I have all of the equipment for it to work, so if anyone has suggestions (apart from upgrading to Windows 8, I don't plan on doing that just yet), let me know and I'll give it a try.

Maybe you could make an extra partition on your hard drive, and try and install windows 8? you would be doing us a huge favour. I really, really hope that it's possible to use the iMac as an external screen for a Windows PC...

 

[hallee]

Maybe you could make an extra partition on your hard drive, and try and install windows 8? you would be doing us a huge favour. I really, really hope that it's possible to use the iMac as an external screen for a Windows PC...

I already tried this (I have the same motherboard). It didn't work for me.

 

[Mac32]

OK, it still might be possible tough, if it's a matter of having the right motherboard and CPU, not necessarily Windows 8.
It should be possible to get a definate answer from Apple about this?

 

[vooblu]

I'll try Windows 8 shortly and see if it works with my hardware.

I think I mentioned this earlier, but the motherboard does work with the Thunderbolt Display which makes me think it's a restriction on the iMac which restricts Target Display Mode to certain hardware only.

 

[drambuie]

It may be that an iMac in TBolt target display mode will only acknowledge, and allow connection to, another Mac.

 

[vooblu]

It may be that an iMac in TBolt target display mode will only acknowledge, and allow connection to, another Mac.

There's a member on page 1 who got it to work with a Windows 8 laptop. I assumed the same until they confirmed it worked.

 

[AT06]

Has anyone tred this method:

Boot into windows on the iMac.
Boot into windows on the PC.
Then try to use the iMac as a secondary display.

My friend does this with windows 7 on both machines and it works very easily with a HDMI to Mini Display cable.

 

[vooblu]

My friend does this with windows 7 on both machines and it works very easily with a HDMI to Mini Display cable.

Your friend likely has an older iMac which supports Mini DisplayPort input. The new iMac's only support Thunderbolt input (no adapters exist which are compatible).

 

[dementor]

Hi!
I have the same problem with my Windows PC and iMac 27 (late 2012)

Here is my pc:
Intel "Core i7-3770K" 3.50ГГц
ASUS "Maximus V Extreme" iZ77 with TB (VGA output support)
PCI-E 4096МБ ASUS "GTX690-4GD5"

I tried to connect iMac as display in Windows 7, Windows 8
with and without LucidVirtu.

Through the original Apple thunderbolt cable.
with settings: primary iGPU in BIOS / without

I connected TB cable to miniDP on my Asus GTX690 videocard.
I also used miniDP<->miniDP cable.

But at this moment I have no result!

I hate Apple for it.

 

[Mac32]

Hi!
I have the same problem with my Windows PC and iMac 27 (late 2012)

Here is my pc:
Intel "Core i7-3770K" 3.50ГГц
ASUS "Maximus V Extreme" iZ77 with TB (VGA output support)
PCI-E 4096МБ ASUS "GTX690-4GD5"

I tried to connect iMac as display in Windows 7, Windows 8
with and without LucidVirtu.

Through the original Apple thunderbolt cable.
with settings: primary iGPU in BIOS / without

I connected TB cable to miniDP on my Asus GTX690 videocard.
I also used miniDP<->miniDP cable.

But at this moment I have no result!

I hate Apple for it.

First, many thanks for trying this out and giving us the results. But really, this is ridiculous. Someone with the correct hardware should approach Apple with their findings, and ask them if they will release a firmware update to support thunderbolt connection with Windows PCs. This is a huge thing for those of us who like to game, esp. a couple of years down the line. There are obviously also plenty of other reasons why some people would want this basic functionality from their iMac.

Edit: I missed the mismatch of ports in this case, but I've yet to see any conclusive evidence from connecting a iMac thunderbolt to PC (windows) motherboard thunderbolt works properly.

 

[vooblu]

I connected TB cable to miniDP on my Asus GTX690 videocard.

Hi,

Thanks for the input so far! The Apple site mentions it must be a thunderbolt > thunderbolt connection (using a thunderbolt cable), so miniDP ports on your graphics card will not work even though the port sizes are identical. I'm assuming you tried the TB port on your motherboard though.

If anyone knows the best way to contact Apple for feedback/suggestions, let me know. It's unlikely I'll get a response, but there's no harm in contacting them..

 

[dementor]

Hi,
so miniDP ports on your graphics card will not work even though the port sizes are identical.

Yeah, I know. But. In a desperate situation.
I tried by TB<->TB cable, and by miniDP<->miniDP.
One of the reason is - I read about backward compatibility TB<->miniDP but without audio signal. Now I know - it's not so.

FYI: if hold the "T" button at startup of iMac - it will automatically load in target disk mode. But it does not change the situation.

And also, I tried to find some ext. device for converting miniDP/DVI/HDMI to Thunderbolt - not found. Only is in opposite direction.

 

[vooblu]

Yeah, I know. But. In a desperate situation.
I tried by TB<->TB cable, and by miniDP<->miniDP.
One of the reason is - I read about backward compatibility TB<->miniDP but without audio signal. Now I know - it's not so.

FYI: if hold the "T" button at startup of iMac - it will automatically load in target display mode. But it does not change the situation.

And also, I tried to find some ext. device for converting miniDP/DVI/HDMI to Thunderbolt - not found. Only is in opposite direction.

Hello,

Holding down the 'T' key actually starts the mac in Target Disk Mode, not Target Display Mode (a common mistake).

I quickly sent Apple some feedback using their iMac Feedback Form. While I don't expect a reply (or any firmware updates), the page says that all feedback is passed onto the iMac team, so if that happens that's good enough with me.

 

[dementor]

Hello,
Holding down the 'T' key actually starts the mac in Target Disk Mode, not Target Display Mode (a common mistake).

Thanks a lot!

 

[dementor]

Hi.
So, after several unsuccessful attempts to connect to iMac Windows PC through TB, I decided to buy another display from Dell. Now consider a return iMac back to the store.
Sorry, but in this case Apple screwed up.

 

[drambuie]

There's a member on page 1 who got it to work with a Windows 8 laptop. I assumed the same until they confirmed it worked.

Now we're getting somewhere. The mutiplexing of the displayport signal into the Thunderbolt is internal to the Intel Sandy Bridge and Ivy Bridge chipsets. Since a Windows laptop with TB output uses the same mobile chipsets as Apple everything is identical signalwise, and it works. Even the method of injecting a discete GPU's video signal would be the same.

Motherboards are a different animal. Motherboard manufacturers have a tendency for tweaking and customizing things, and that might produce subtle differences in the Thunderbolt+displayport output, that the iMac Target Display Mode circuitry doesn't recognize. Asus had a PCIe card that injected PCIe display card displayport output into the Thunderbolt signal, but that device disappeared. I read somewhere that Intel had that nixed.

 

[vooblu]

Motherboards are a different animal. Motherboard manufacturers have a tendency for tweaking and customizing things, and that might produce subtle differences in the Thunderbolt+displayport output, that the iMac Target Display Mode circuitry doesn't recognize.

The iMac and my motherboard have the same cactus ridge thunderbolt controller, whether that makes a difference or not. As mentioned before, the motherboard also works with the thunderbolt display which makes me think it may be some software limitation that has purposely been added on the iMac to restrict it to certain hardware (and for some reason, the HP laptop slipped through).

If I'm correct, all thunderbolt products need to be approved by Intel to use the "thunderbolt" icon/logo. Since both the iMac and motherboard have been approved and have "proper thunderbolt", they should interact fine.

Honestly, I'm stumped. Hopefully a thunderbolt firmware release fixes this. Wishful thinking.

 

[bkonings]

rMBP running windows -> iMac 2012

Before you go testing different hardware has anyone even tested if an apple Macbook running windows can use a iMac 2012 running osx in target display mode.

I suspect even a macbook pro and an iMac won't support it, and if so your quest to get a PC to use a target display mode iMac running osx is pointless.


This apple faq seems to say it wont work, though im not sure they are referring to a imac running osx.
http://support.apple.com/kb/HT5219?viewlocale=en_US#17

24. Can I use Target Display Mode or Target Disk Mode with Boot Camp and Windows 7 using a Thunderbolt-capable iMac?

No. Target Display Mode and Target Disk mode are not supported using Boot Camp and Windows 7 on a Thunderbolt-capable iMac.



This macrumorstopic seems to indicate it doesn't work: https://forums.macrumors.com/threads/1420154/

 

[Mac32]

What about windows 8 and thunderbolt support?

 

[benjaminfoden]

Where did these ideas come from?

I think there's some fancy restrictions going on somewhere within the UEFI of the iMac, possibly to ensure that only approved computers/cards can connect. Apple only claim the Target Display Mode works with Apple Branded computers, therefore this might well be the case.

For those of you who are trying Mini DP, that will not work. Whilst they both have the same connector, they are two completely different technologies wit different signals. The iMac will not recognise any machine connected from a mini DP output.

 

[vooblu]

Apple only claim the Target Display Mode works with Apple Branded computers, therefore this might well be the case.

The iMac spec page says this, which doesn't specifically restrict it to Apple devices: Support for Target Display Mode via the Thunderbolt port using a Thunderbolt to Thunderbolt cable (sold separately)

I suspect even a macbook pro and an iMac won't support it, and if so your quest to get a PC to use a target display mode iMac running osx is pointless.

There's a user on page 1 who got their windows laptop to work. Assuming we aren't being trolled, it means there's some hardware configuration which seems to work.