27" iMac displayport Input

That about sums it up I think. I am curious for someone with the 4xxx series card to try the 27'' imac since it is confirmed also that the 5xxx series does not work with the 24'' cinema display but the 4xxx does.

You forgot :)

(iii) AppaYipYip is a douche. Dishonesty is not appreciated when trying to help people get things working.
 
I have tracking for my quad core imac showing it should be here on Friday- so assuming that my DP to mDP cable (is it wrong to type DP like that???) comes in I should be able to work on it over the weekend with the 5870. I will be suprised if I cannot make it work- my guess is that the people who tried it before did not set the res properly - i.e. they are mac guys playing with a pc rather than the other way round. Anyway- this weekend it is!!!
 
I bought a 5770 with the intent of hooking it up to my iMac but had no luck. The issue is that both Windows and Catalyst fail to detect that a monitor (i.e. the iMac) is even attached to the DisplayPort so you can't enable the monitor or configure the resolution for it. I even tried booting up with no monitor attached (and then plugging in the iMac) and creating a custom monitor INF with PowerStrip and nothing worked.

At this point I think there is either a hardware or driver incompatibility between the Radeon 5000 series and the iMac in target display mode. The same issue seems to exist with the 24" Apple LED displays as well.

Hopefully it's just a driver issue and will be fixed at some point in the future, but after trying the beta 9.11 drivers with no luck, I think it could be a long wait.

Since I'm still within my 30 day window, I'm returning the 5770 and exchanging it for a 4890 since I've seen confirmations that this DOES work at least with the 24" Apple LED display. Hopefully I'll get the new card by Friday and try this out with the 27" iMac.
 
circularreference said:
I bought a 5770 with the intent of hooking it up to my iMac but had no luck. The issue is that both Windows and Catalyst fail to detect that a monitor (i.e. the iMac) is even attached to the DisplayPort so you can't enable the monitor or configure the resolution for it. I even tried booting up with no monitor attached (and then plugging in the iMac) and creating a custom monitor INF with PowerStrip and nothing worked.

At this point I think there is either a hardware or driver incompatibility between the Radeon 5000 series and the iMac in target display mode. The same issue seems to exist with the 24" Apple LED displays as well.
Click to expand...

What are you connecting them with? I read elsewhere several weeks ago that you need a bi-directional miniDP to DP cable, and that only uni-directional cables were out so far.
 
What are you connecting them with? I read elsewhere several weeks ago that you need a bi-directional miniDP to DP cable, and that only uni-directional cables were out so far.
Click to expand...

I'm using the following DisplayPort to min DisplayPort cable:
http://www.newegg.com/Product/Produ...mini_displayport_cable-_-12-270-262-_-Product

Why would directionality matter on a mDP/DP cable? Mini DisplayPort has the same pinout as DisplayPort, just with a smaller connector.

The only issues I've seen posted with directionality were people trying to use a mDP -> DVI/HDMI in the opposite direction, which of course will not work.
 
Thanks for all the efforts!

I think if we see the 4xxx works on the 24'' cinema display and the 5xxx does not then it is an ATI problem not an apple one or a cable issue.

What will be interesting is if the 4xxx series works on the 27'' but I only care about using the PC on the mac because of the 5870 I have otherwise I can just run bootcamp.
 
circularreference said:
I'm using the following DisplayPort to min DisplayPort cable:
http://www.newegg.com/Product/Produ...mini_displayport_cable-_-12-270-262-_-Product

Why would directionality matter on a mDP/DP cable? Mini DisplayPort has the same pinout as DisplayPort, just with a smaller connector.

The only issues I've seen posted with directionality were people trying to use a mDP -> DVI/HDMI in the opposite direction, which of course will not work.
Click to expand...

This is the best info I can find on cabling into the 27" iMac:

This thread was the first I read, which gave me more questions than answers about bi-directionality:

http://discussions.apple.com/thread.jspa?threadID=2205448&tstart=0

It did point me towards this article:

http://www.appleinsider.com/article..._27_imac_only_supports_displayport_input.html

which links to this article:

http://www.appleinsider.com/article..._imac_designed_to_also_work_as_a_display.html

which in turn links to this cable:

http://store.apple.com/us/product/TX706
 
As hornkiku23 stated, if a 4890 works with the 24" cinema display (using a mDP/DP cable), I think it's safe to assume the cable is not the issue here with the 5000 series. The 4890 I ordered is shipping today, so hopefully I'll get it by Friday and find out for sure.

If the 4890 works fine with the iMac, I think it puts the blame squarely on ATI (either a driver issue or a hardware problem).

If the 4890 does NOT work with the iMac, then it may actually be an Apple issue. But I'm hoping this is not the case or I'll have to eat another restocking fee.
 
(I know I can just google for benchmarks, but I'm lazy and all)

How does a 4890 stack up to a 5870? From what I remember, 4890 was latest and greatest as recently as six months ago. Is it worth getting over the stock 4850 in bootcamp for gaming at that sweet, sweet 2560p, or should I hold out for a 5xxx solution down the road?
 
elleana said:
(I know I can just google for benchmarks, but I'm lazy and all)

How does a 4890 stack up to a 5870? From what I remember, 4890 was latest and greatest as recently as six months ago. Is it worth getting over the stock 4850 in bootcamp for gaming at that sweet, sweet 2560p, or should I hold out for a 5xxx solution down the road?
Click to expand...


The 5870 stomps all over the 4890. For 2560x1440 gaming, the 5870 is definitely the way to go; the 4850 doesn't really have the power for that resolution.
 
OK- So I got the imac- and DAMN is that display nice. I spent some time moving things over- software and whatnot before trying the 5870 to 27" connection. The 5870 is seeing a "CRT Display on VGA" which I see as positive, because I should be able to set the resolution properly to match that of the imac. When plugged in- the imac goes blank, though i can still hear active programs running due to the audio coming from the speakers.

The 5870 will let me make a display group- or add the monitor- but nothing will display on the imac- just a blue screen. I have not been able to find a way to adjust the res on the "CRT Display on VGA"- mostly due to it being late and me having a job. I am not a n00b- it is not acting normally. My feeling is that if I can get the res set properly, that I will get it working. So far NADA.

That is what I have so far. Any input would be welcome.

Running W7 RC by the way and most recend drivers (though I am not at home so can't give you the version).

As a side not- Evil Sofa is right in that a couple of games that I tried struggled with the resolution due to the 4850. Otherwise VERY cool for videos and graphics. DP out to my cintiq works great!
 
C0Y0TE said:
The 5870 is seeing a "CRT Display on VGA" which I see as positive, because I should be able to set the resolution properly to match that of the imac. When plugged in- the imac goes blank, though i can still hear active programs running due to the audio coming from the speakers.
Click to expand...

Where are you seeing "CRT Display on VGA"? In Device Manager or in the Catalyst Control Center?

When I attempted this with a 5770, Windows always had 3 monitors listed in Device Manager (I presume for the 2 DVI outputs and the DisplayPort output) whether I had something plugged in or not.

I was never able to get the iMac display to show up in CCC (other than for a split second if I quickly plugged in the iMac to the 5770 and rapidly clicked "Detect Displays"). If you're seeing the iMac listed in CCC, then it sounds like you might have gotten further with the 5870 than I was with the 5770.
 
C0Y0TE said:
The 5870 is seeing a "CRT Display on VGA"
Click to expand...

Uh oh. The iMac's mini-DP port can output VGA, DVI, HDMI and DP, but can only input DP. The restriction on only inputting DP is hardcore - you will never be able to get VGA working.

If the video card is attempting to use VGA, it will never succeed, no matter what you do. You need to make the video card use DP.
 
Ok, my 4890 came in today and I can confirm that it DOES work with the iMac.

I would have preferred the 5770 (slightly cheaper, less power hungry) but until ATI updates their drivers (assuming it's not a hardware issue) it looks like the 4890 is the only way to connect your PC to your iMac.
 
Thanks for checking that out.

How about the 2560x1440 rez for games. Does it show up at all in anything?

No game I have lists that as a 16:9 choice on my dell 3007.
 
circularreference said:
Ok, my 4890 came in today and I can confirm that it DOES work with the iMac.

I would have preferred the 5770 (slightly cheaper, less power hungry) but until ATI updates their drivers (assuming it's not a hardware issue) it looks like the 4890 is the only way to connect your PC to your iMac.
Click to expand...

so lets see thats that long awaited photo of it working :)
 
hornkiku23 said:
Thanks for checking that out.

How about the 2560x1440 rez for games. Does it show up at all in anything?

No game I have lists that as a 16:9 choice on my dell 3007.
Click to expand...

That is because it is not an option on your monitor- you have the 2560 x 1600. You could probably go into the config file for the game (Doom3 for instance) and make that res available. I wonder if that would give you black bars on the top and bottom of the screen.

If the video card is attempting to use VGA, it will never succeed, no matter what you do. You need to make the video card use DP .
Click to expand...

The CCC is just reporting that as the connection (and it wasn't there before). I am not ACTUALLY using VGA- I am using display port of course.

A little busy tonight, but will give it another go tomorrow. I am very encouraged to hear that the 4890 works. That tells me that this is probably some type of driver or firmware issue on the ATI side. I am sure that this will be working by the time Diablo 3 comes out in 2011! Woo Hoo Diablo on the 27":rolleyes:

Ok, my 4890 came in today and I can confirm that it DOES work with the iMac.
Click to expand...

Circular- can you give me some of the details. Are you setting this up as a display group in CCC? How does it appear in windows monitor settings? Did you do anything special to the imac- settings at all? What version drivers and for that matter is this win7, xp, or vista on the PC? Thanks for the help!
 
Last edited:
C0Y0TE said:
Circular- can you give me some of the details. Are you setting this up as a display group in CCC? How does it appear in windows monitor settings? Did you do anything special to the imac- settings at all? What version drivers and for that matter is this win7, xp, or vista on the PC? Thanks for the help!
Click to expand...

Here were my steps:

1) Installed 4890 into my PC
2) Connected it to a DVI monitor (did not connect the DP port)
3) Booted up Vista (64-bit) and opened CCC (I'm using version 9.10)
4) Plugged in my mDP/DP cable between the 4890 and the iMac

At this point the iMac went blank and then CCC immediately recognized the monitor (it labels it as a "Color LCD, DFP, DisplayPort(TM), 2560x1440 @ 60Hz") and I was able to set it as my primary monitor and disable the DVI monitor. These exact same steps did NOT work with the 5770.

I can also use resolutions lower than 2560x1440 as the ATI driver will just scale. In CCC you can configure whether these lower resolutions will be stretched to fill the screen, scaled while maintaining aspect ratio (i.e. black bars on the sides), or centered (i.e. black on the sides and top/bottom).

After playing with that for a while, I completely unplugged the DVI cable and rebooted and was somewhat surprised to see my BIOS boot up screen on the iMac display. I had thought the iMac did not have any scaling hardware (thus could not handle resolutions under 2560x1440) but perhaps the 4890 is smart enough to sense the capabilities over the DP link and do the scaling itself.

The fact that I can see my BIOS screen on the iMac display (long before the Vista video card drivers come into play) leads me to believe there may actually be a hardware/firmware issue with the Radeon 5000 series and not simply a driver issue.

For what it's worth, I also booted up Windows XP (32-bit) and everything worked just like in Vista. Also, my iMac is running OS X 10.6.2, if that has anything to do with it.
 
spyder_flex97 said:
so lets see thats that long awaited photo of it working :)
Click to expand...

What exactly do you want a photo of? I'm not sure a pic of the Vista desktop on the iMac screen is all that interesting since you can do that with Boot Camp :)

If I get some time this weekend I guess I could post a photo of the BIOS boot up screen on my iMac or the display listed in CCC or something like that.
 
As much as I like apple products I am so sick of stuff like this over the years for people who want to integrate them into a larger more sophisticated setup.

I remember the same crap with the cinema displays and bios years ago.

The real issue here for me is the above 1920x1200 pc display market is dead and has been for years.
 
I just got my new iMac 27" quad core shipped in and at the same time i built a PC banking on the fact that I would be able to use the iMac as a monitor for it. The PC has a ZOTAC Nvida 9400 GT DP video card with the displayport output. I have a displayport to mini displayport cable running from the PC to the iMac. There seems to be a catch 22 problem I am having though. The PC wont recognize the iMac as a possible monitor unless it is switched into target mode, and the iMac wont switch into target mode unless it sees a video signal coming in (or so i think). Do you guys have any idea on how I can get this to work, or if it ever will? For those of you with the iMac, if you have nothing connected to the display port and you press command F2 does anything happen? Nothing happens on mine whether the cord is connected or not.

If this will never work, what card can i buy that will work. I am looking for the cheapest thing possible, the PC isn't used for anything graphics intensive, I just want to eliminate having 2 monitors on my desk!!
 
TheDanimal said:
For those of you with the iMac, if you have nothing connected to the display port and you press command F2 does anything happen? Nothing happens on mine whether the cord is connected or not.
Click to expand...

Nope. Cmd+F2 only seems to work for me if I have something connected. Unplugging and plugging the DP cable should have the same effect as pressing Cmd+F2 though.

Also, make sure you are using the Wireless Apple keyboard that came with your iMac, not some other keyboard. The keystroke is technically "Cmd+Brightness Up" (which happens to be the F2 key on the Apple Wireless Keyboard).

Finally, one more thing to check is if you've toggled the System Preference for function keys, you may actually need to press Fn+Cmd+F2. Hope that helps.


TheDanimal said:
If this will never work, what card can i buy that will work. I am looking for the cheapest thing possible, the PC isn't used for anything graphics intensive, I just want to eliminate having 2 monitors on my desk!!
Click to expand...

The Nvidia 9400GT is an interesting data point. If you can get that to work with the iMac, it provides further evidence of there being a specific issue with the Radeon 5000 series.

I know for sure the following card (Radeon 4890) DOES work:
http://www.newegg.com/Product/Produ...on_4890_displayport:_1-_-14-102-848-_-Product
 
Thanks for your help. It's good to know that at least soemthing does owrk, however that is a lot more than I was looking to spend on a card. The Nvidia card that I am using was only $40! I am going to look and see if ATI has anything cheaper in the 4000 series with a display port.
 
TheDanimal said:
The Nvidia card that I am using was only $40! I am going to look and see if ATI has anything cheaper in the 4000 series with a display port.
Click to expand...

So what happens when you plug a DP/mDP cable between this video card and the iMac while the PC is powered on? Does the iMac screen go black for a few seconds and then switch back to Mac OS?

Do you have anything else connected to the Nvidia card (i.e. a DVI monitor) in addition to the iMac?

I'm curious to see if the Nvidia card will work with the iMac. I considered buying that same ZOTAC card but decided to pony up the extra cash to get a video card that at least has a chance and running some games at 2560x1440.
 
I have tried every possible combination of hooking up the cable before and after the PC is turned on, with and without my VGA monitor connected. I can not get the iMac to do anything. It looks like the iMac wont sense any input unless I can get the card to output to it, and the card wont output anything until it senses a monitor. VERY frustrating.

This is the cable I am using, I dont think it is the issue at all....
http://www.monoprice.com/products/p...=10246&cs_id=1024606&p_id=6008&seq=1&format=2
 
TheDanimal said:
I have tried every possible combination of hooking up the cable before and after the PC is turned on, with and without my VGA monitor connected. I can not get the iMac to do anything. It looks like the iMac wont sense any input unless I can get the card to output to it, and the card wont output anything until it senses a monitor. VERY frustrating.
Click to expand...

Odd. I get an immediate reaction from the iMac if I plug or unplug the mDP/DP cable while the PC is on. I got at least this even with the Radeon 5770.

You might have just gotten a bad card. For something in that price range, I would not be surprised if the quality control on the DP port isn't all that great.

Doesn't the card also have a HDMI port? Do you have a way to test that? Who knows, maybe there is some configuration you have to do in the Nvidia control panel before the other outputs will get enabled.
 
I tested the HDMI on my tv and it worked, and I have had the DVItoVGA hooked up working as well.
 
TheDanimal said:
I tested the HDMI on my tv and it worked, and I have had the DVItoVGA hooked up working as well.
Click to expand...

And I assume you didn't have to do anything to enable the HDMI output before it worked?

What version of Mac OS are you running on the iMac? You might want to try 10.6.2 if you haven't already updated.
 
I'm running 10.6.2. I first used my macbook pro's HD and made a clone and installed it in my iMac as sson as i got it. I thought that might be the problem so I did a fresh install of 10.6.2 from the iMac install disks, and still no luck. And yes, when I plugged the HDMI in it automatically came up in the Nvidia control panel and was easy to run in a clone setup. This is so frustrating!!!!!!
 
It's still possible you have a bad card, but I'm starting to wonder if maybe Apple has more to do with this problem than I first thought.

I tried a couple of experiments last night to better understand how the iMac's target display mode really works. If I reboot the iMac and start pounding Cmd+F2, it doesn't switch inputs until after the gray Mac OS boot up screen right before the GUI starts to load. I also tried booting into another OS (using a Ubuntu Live CD) and Cmd+F2 does NOT work.

So it appears that not only does the iMac have to be powered on, but Mac OS also has to be running for target display mode to work. This implies that the video driver on the Mac OS side may have a hand in this whole compatibility mess.

Since the Radeon 5000 series cards were just recently released, perhaps the iMac video card drivers have not been updated to support them yet? This could explain why the 4890 works (Apple uses several Radeon 4000 series cards in their current lineup) and the newer 5000 series does not, but I'm not really convinced.

Of course with this line of logic, I would also expect your Nvidia 9400 GT to work since Apple uses the 9400M in many of their computers (but perhaps the 9400M and 9400GT are significantly different driver-wise?). Also this doesn't really explain why the 5000 series doesn't work on the 24" ACD (where Apple drivers are not a factor).

Now I'm curious whether target display mode works in Boot Camp or not. I'm guessing no, but I could be wrong. If I get some time tonight, I'll try it out.
 
Target display mode is a feature of 10.6.2 and will not work unless that system is booted up first. That I know.
 
I just ordered a Radeon HD 3470 with displayport output. Hopefull that card will work, if not it was only $35.
 
Yeah it would be good to find more than one video card that works with the iMac. Do post your findings.

I tried doing Windows XP via Boot Camp yesterday (to see if target display mode will work outside of Mac OS) but after installing the Boot Camp video drivers, XP just boots into a blank screen. I'll have to mess with it some more this weekend.
 
Ooops! I figured out why Boot Camp wasn't working - I used the retail Snow Leopard DVD to install my Boot Camp drivers (since it was handy) not thinking that this slightly predates the new iMacs and likely does not have the correct drivers. After reinstalling the drivers with the DVD that came with my iMac, all is well.

And, like I expected, target display mode does NOT work in Boot Camp. It seems that Mac OS X 10.6.2 (and the version of 10.6.1 that came preinstalled on the iMac) either have some custom video drivers or a separate process running that enable target display mode to work.

If that's the case, I would assume if Apple wanted, they could enable a picture-in-picture or split screen display on the iMac down the road, which would be pretty cool. You could fit two 1280x1024 screens side-by-side on the iMac.

On a related note, AMD is finally responding to the support ticket I opened like 2 weeks ago. The response is braindead as expected, but I informed them of the situation with the 4890 so we'll see if that goes anywhere.
 
Not me, I've paid enough restocking fees already. But if someone wants to send one my way, I'd be happy to try it out :)

The 5970 would be another interesting data point, but my money would be on it having the same issues as the other 5000 series cards.
 
hornkiku23 said:
(iii) AppaYipYip is a douche. Dishonesty is not appreciated when trying to help people get things working.
Click to expand...

:eek::eek:

Wow....I have spent years on this forum and seen the likes of you come and go....

I happen to work for Apple (have worked for them for over 5 years) and have nothing to prove. However, I will let you in on a little secret:

http://www.atlona.com/Atlona-DVI-to-Mini-DisplayPort-Converter-p-17859.html

You're welcome.

BTW: There is this little thing called an NDA that employers make people sign. Perhaps you should also read about those:
http://en.wikipedia.org/wiki/Non-disclosure_agreement


You can now return to being a troll.
 
You are a very sad person.

1. The altona does not support the full 2560x1440 yet. They are working on it. (If you had lied and said you worked for altona instead of apple we might have believed it.) Good liars are usually intelligent.
2. You do not work for apple in any development capacity that would give you access to an NDA on hardware. Helping soccer moms put songs on there ipod does not count.
3. Apple does not have an NDA on getting the imac 27 to work with a pc video card. That is just plain stupid to even try and claim.
4. Your claims on this forum are outright lies and there is nothing to do to prove your claim because it does not exist as you stated.
 
Back to the real discussion.

The 5970 has a mini displayport out not a regular displayport. What do you think of that circular?
 
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