Connecting monitor to integrated, but utilising dedicated

[vooblu]

Hi everyone,

Hopefully this is the right forum for this question.

I have a PC and I'm planning on using an iMac as a monitor. The only way to do this is by using a thunderbolt cable between two thunderbolt ports. My motherboard has a thunderbolt connector, but that means it can only use the integrated graphics which isn't ideal for gaming.

Apart from Virtu MVP, is there a way for me to utilize my graphics card if the monitor is plugged into my motherboard?

Same thing as this (search that page for "Technically"), but I wasn't sure if my graphics card + motherboard have the right connections.

Hopefully someone can help. My new mac comes on Tuesday so I would love to get this sorted! Thanks!

 

[spoffle]

What graphics card do you have?

Thunderbolt is just DisplayPort, with added functionality. So you will be able to connect your graphics card to the iMac with just a mini display port cable if you have a graphics card with mini-DP outputs.

If not, you'll need a full size DP to mini DP adapter/cable.

 

[vooblu]

Hi spoffle,

The graphics card is linked in the first post NVIDIA GeForce GTX 670 GPU My motherboard is a GA-Z77X-UP4 TH

Even though thunderbolt is DisplayPort as you mentioned, the iMac can only be used as a monitor when it's connected between two thunderbolt ports using a thunderbolt cable (it's very specific on the apple website), so unfortunately I can't connect it to my graphics card directly using a mini dp cable.

 

[Orcvader]

Well the card has a Displayport, have you tried connecting the 670 directly to the iMac anyway? No harm in trying.

EDIT: Looks like it works: http://techtips.salon.com/use-imac-pc-monitor-1648.html

Therefore, it doesn't need to be Thunderbolt. Thunderbolt is just mini-Displayport anyway, with added capabilities, but when doing displays, it just acts as regular Displayport mode.

All you need is a Displayport (male) to mini Displayport (male) cable.

 

[spoffle]

Whoops! I didn't notice it was linked.

Displayport and Thunderbolt are the same thing, the only reason Apple say that is to try and sell you their expensive Thunderbolt cables and devices.

So you can be sure it'll work.

 

[vooblu]

Well the card has a Displayport, have you tried connecting the 670 directly to the iMac anyway? No harm in trying.

EDIT: Looks like it works: http://techtips.salon.com/use-imac-pc-monitor-1648.html

Thanks for the reply Orcvader. The guide you posted is for 2009+2010 models which supported mini displayport input. I have seen countless members on apple-related forums try this on 2011+2012 models with Displayport cables, but the only people who are successful are those who use thunderbolt cables between two thunderbolt ports. I will of course try it with other cables, but I'm extremely confident it will not work, as stated on Apples website. I believe it's a restriction with their Target Display Mode feature.

Are either of you aware if the loop-back cable technique from my first post is possible with my graphics card + motherboard combo?

 

[Orcvader]

Just had a look at it, looks quite funky:

I guess if you was to do that it will work. What motherboard do you have? However I would imagine Virtu MVP will give about the same performance (maybe even extra as it allows both integrated and discrete to work together) and will have less wire mess.

 

[vooblu]

Motherboard is linked in an earlier post. GA-Z77X-UP4 TH

I've tried Virtu MVP (last attempt was last night with latest drivers), but it's extremely buggy with games which is the primary use for the PC.

My only concern is that the motherboard doesn't have a display port (only thunderbolt ports, which can be used as mini displayport in this case, I assume). I don't expect anyone to know if it'll work for sure, but what cables would you recommend if I were to try this technique? Keeping in mind I can't use the display port one as shown in the image.

Thanks again for the reply!

 

[Orcvader]

Well, at least the Thunderbolt controller is one of the listed that works.

But reading this:

The motherboard must have a Light Ridge or Cactus Ridge 4C controller.
Your motherboard must have a DisplayPort input port to route the second display signal.
You motherboard must have a built-in DisplayPort output port (from Intel HD Graphics 3000/4000), which is looped back to the input port.

Looks like you're stuck with Virtu. Have you tried the Virtu drivers directly from the Lucid site?

 

[vooblu]

Yeah, I wasn't sure if the other inputs on the motherboard like HDMI would work (since I don't have DisplayPort). Since thunderbolt is DisplayPort though, it makes sense that DisplayPort would be the only one which works.

I've tried a huge combination of Virtu driver versions. The current version doesn't work at all with Battlefield 3 (the game crashes before it even starts). Older versions kind of work, but have major glitches and the game crashes after roughly 30 minutes. As far as I know, they're supposed to be releasing v2.0 of Virtu MVP this year but I haven't seen many news posts about it yet.

Assuming I can't connect my motherboard + graphics card with a HMDI cable and then send the data through TB to my iMac, then I guess I'm out of options.

Edit: I'm not sure how much you know about this topic.. but does this make sense:
1. Connect the graphics card (from its DisplayPort output) to the motherboard's thunderbolt input using a DisplayPort > mini DisplayPort cable (since mDP and TB have identical inputs).
2. Connect the iMac to the 2nd thunderbolt port on the motherboard using a thunderbolt cable. Would that be able to utilize the power of the graphics card? I honestly have no knowledge of this myself, so it's all assumptions

 

[Orcvader]

You could give it a try. No idea if it will work.

Have you considered getting a seperate monitor for the PC instead? Or is this to save desk space?

 

[vooblu]

I currently have both the iMac and PC monitor on the same desk, but it's extremely cluttered so the reason is to save desk space.

Thanks again for the help. If anyone else has any idea if the technique in post #10 would work, please let me know. I'm checking this topic almost hourly for new replies, so your time won't be wasted.