Tests confirm Apple's 27" iMac only supports DisplayPort input - Page 4

The 4xxx series cards were used successfully with this adapter with the 24'' inch cinema display via display port.

Could it be an issue of resolution? Perhaps it's only the resolution signal that is not properly transmitted in reverse, much as with the old Mac Video>VGA adapters of old?

That is possible but you would think a passive adapter would just pass the info along. I have my desktop hooked up at 2560x1600 on my pc and I have put converters such as hdmi and dvi extensions on the line and it always works fine.

.....and furthermore also the ati/nvidia cards scale resolutions so it could just output at 1920x1080 or whatever and it should display a scaled image. My monitor is a native 2560x1600(dell 3007) and it can display any resolution hooked up to the video card(640x480 through 2560x1600) but will not display anything from any other non scaled source such as an xbox or blu ray player, it has to be native then.

So if the adapter did in fact not support the higher resolution the video card would just default to something lower and scale it.

just tried the 9.11 beta drivers and no go..not getting the sync message anymore either...with cmd+F2 sometimes all screens go black and catalyst appears to be trying to sync with a blue spinning circle and adding a device sound that windows makes but eventually fails....also tried target display mode with iMac resolution down to 1920x1200 and still no luck


sure amd is aware of situation by now, if they are the culprits....

thanks
jed

Well, I have been reading through several different forums and have been on the edge about my purchase of the new 27in iMac... this what i have determined. dual reasons for purchasing this system; want a Mac desktop and make the full switch to apple and to connect my PS3 to this through the new input. same thing everybody else is dying to do.
here is the good news... as previously mentioned the only way to functionally connect the ps3(or any other stand-alone, non-miniDP connection) to the 24in Cinema display was through the use of two different adapters. the Atlona DVI to mini DisplayPort Convertor (to change your signal) and then to deal with the difference in native resolution you needed the HDMI/DVI Scaler. this process has been confirmed to work with the 24in Apple Cinema Display... like i said... I'm sure you are all aware of this already.
Not so easy with the 27in iMac. First step would work but the second step does not because the iMac's native resolution is a staggering 2560x1440... well above the max single-link DVI connection of only 1900x1200 (basically full HD...1080p)...... drum roll please...... I just got off the phone with Atlona to address this issue and the service rep told me that....in about a weeks time.... the new model of this same scaler will come out and WILL be able to upscale to the level of 2560x1440. While there are no guarantees here and I am going off of the word of this Rep and his project manager... this is so damn exciting news, right? granted some tests would be required for the 100% compatibility and all that stuff... but if I am reading correctly this would solve the one issue everybody is having. native resolution. godspeed!
oh yes... the Rep said to call before you purchased it... he said about a week and it would be out. but basically you want to call to confirm you are in fact purchasing the NEW model that upscales to the correct resolution. good luck!
Atlona DVI-to-mini Display Convertor....model: AT-DP200
Atlona HDMI/DVI scaler - model: AT-HD560 (call to ensure correct version)

Is the 4xxx card capable of outputting 2560x1440 over a single port?

with the connection of dp->mdp cable from the ati 5800 series graphics card to the iMac 27 there are evidently compatability issues...it flat out doesn't work...there is a 20 pin out for both the dp and mdp which though aren't "physically" numbered the same am sure the pins correctly correspond when dp->mdp cable is manufactured....


http://en.wikipedia.org/wiki/DisplayPort
http://developer.apple.com/softwarel...ions111908.pdf

displayport spec v1.1a is the present updated spec which VESA just recently included Apple's mdp to that dp spec

now is this the hold up? being that apple's mdp has just been standardized do we need all the dp manufacturer's to come in line with Apple or is it Apple to get in line with v1.1a dp spec or both? You would think that dp manufacturers are manufacturing according to the present VESA spec so that leaves Apple to get its act together....

the future interoperability between dp and mdp should more or less be pnp you would think!!! so is it it just a matter of time?

question....if you were to take the 5870 6DP Special Edition and output it to the imac 27 would it work today? you would most hopefully think so, wouldn't you?
http://www.tcmagazine.com/comments.p...=30749&catid=2

Physically the 5870 and 5870 6DP aren't much different except for the mdp's (see pg.7)
http://translate.google.com/translat.../view/16308/1/


So Apple and AMD what are we waiting for? Is it you Apple or is it you AMD that we are hearing the deafening silence from in why a amd dp cannot connect and work when cabled into an imac 27 mdp?

If i were to wage a guess I’d say it’s Apple
That is a tough question, but I’d wager the problem resides within the iMac itself. I still havent’ seen how the mDP port connects to the GPU. The import feature is atypical so depending on how Apple or ATI designed it to work it may just be a driver issue, it could be part of the design to only work with other Macs or it could be a design issue. As lame as that sounds I wouldn’t put it past Apple.

For another example of Apple doing wonky things with standardized HW check out this link:

•

http://www.anandtech.com/mac/showdoc.aspx?i=3672&p=5

Apple has been "anointed" by VESA and incorporated into the "refreshed" displayport spec v1.1a......being this is fairly recent news and that the v1.1a spec has been around since Jan 2008 I would agree that the problem most likely lies with Apple....Apple opened the door, VESA entered and now it is up to Apple to entertain.....

Technical Specification

* Hot pluggable: YES
* Audio signal: Optional, 1-8 channels, 16 or 24 bit linear PCM, 48/96/192 kHz sampling rate, uncompressed, max. 6.144 Mbit/s bit rate
* Video signal: Optional, maximum 2560x1600 resolution
* Bandwidth: 1.62 or 2.7 GHz symbol rate, 1/2/4 lanes (total 5.184 or 8.64 Gbit/s; latest version 1.1a, 10.8 Gbit/s) plus 1 Mbit/s for AUX CH (for additional data)
* Protocol: mini-packet
* Electrical:
o +3.3 V
o Max voltage: 16.0 V
o Max current: 500mA
* 10.8 Gbit/s forward link channel supports high resolution displays with a single cable.
* 8B/10B data transmission (up to 2.7 GHz symbol rate, up to 4 lanes, 8B/10B modulation).
* Reduced bandwidth transmission for 15 metre cable (at least 1920x1080p60, 24 bpp).
* Full bandwidth transmission for 2 metre cable.
* Supports color depth of 6, 8, 10, 12 and 16 bits per color component.
* Supports YCbCr color space (ITU-R BT.601-5 and BT.709-4), 4:2:2 chroma subsampling
* Supports legacy signal streams (analog and DVI/HDMI]]); backward compatibility achieved with adapters/dongles
* 128-bit AES DisplayPort Content Protection (DPCP) support, and support for 40-bit High-bandwidth Digital Content Protection (HDCP) from version 1.1 onwards.
* Supports internal and external connections so that one standard can be used by computer makers reducing costs
* Open and extensible standard to help with broad adoption

It does appear to be a problem solely with the iMac 27, but Im still not convinced that its all Apples problem at this point. The ATI GPU seems to be unique in that it allows for input.

Or could it really be something as silly as the tested adapters not allowing for two-way signaling which is why mDP-to-mDP cables from a MacBook seem to work?

The iMac's DisplayPort input works fine when connected to a PC with a Radeon 4890:
http://www.hardforum.com/showthread....1462524&page=3

There is an apparent hardware/firmware issue with the Radeon 5000 series that is preventing it from working with the iMac (and the 24" ACD as well). It seems to be an ATI issue, not an Apple issue at the moment.

Thanks for the info and welcome to the forum. As stated in your link, I wish I would have read that the 24 LED Apple display with mDP also dont work with the 5xxx series cards. The idea of the uni-directional cable being the problem never really sat well with me. Hopefully well see more confirmation on this tomorrow.

You would figure that before shipping the displayport of the 5800 series was both spec'd externally and internally according to VESA v1.1a. According to the spec all should be plug and play, don't get it...are they that lame!!?? Is that the reason for the last week or 2 you haven't been able to find a 5800 except on Ebay? These cards are backordered to the moon!! Was production stopped?

Alright AMD fess up will you!!

Hope that is not the case and is just firmware/driver issue, otherwise my card is going back on Ebay, quick!

**No "public" mention by AMD's Product Manager of anything wrong with 5800 except 40 nm production
http://www.hardocp.com/article/2009/...refor_art_thou

=====================

relevant posts by circularreference @ hardforum
#54 http://www.hardforum.com/showpost.ph...0&postcount=54
#58 http://www.hardforum.com/showpost.ph...2&postcount=58

seems to confirm it is AMD's problem....thanks circularreference

Tests confirm Apple's 27" iMac supports the Radeon HD 5970 out of the box!!
screenshot from iMac screen



was tired of waiting for the solution for the 5870 series card (to date as far as is known still does not work with iMac 27) upgraded to the 5970 and whoooaaa!!! out of the box without even installing ati drivers (windows installed generic) the iMac took off into targetdisplay mode....afterward installed drivers that came with the PowerColor card and played a little MW2 all maxed on the iMac @ 2560 x 1440 - 100 FPS + on little I played and picture is beauuuuutifull

so there is hope for gaming pcs to use the iMac 27" as an external monitor!!! now if you can just find the 5970's.....think they sold out everywhere within an hour or so upon release.

signed
happy camper

What cable are you using to connect the 5970 to the iMac?

Also, I assume the card outputs to the iMac from the moment you power the PC on (i.e. you can see your BIOS startup screen on the iMac)?

had the BYTECC Mini DisplayPort Male to DisplayPort Male when tried the 5870 and in the box along with the PowerColor card there came a short DP female to Mini DisplayPort Male adapter.....still have an adapter from monoprice coming that ordered before knew that one would be packaged with the 5970

there has been no display at all of the iMac bios screen....when connected to the 5970 mDP,
starting the PC from sleep with the iMac in sleep the video card doesnt like it and sorta wigs out and the card fan speed accelerates for a moment with neither the imac or other display displaying anything...have to reboot to have it work right again...there must be a proper exit procedure in CCC when using the iMac as a display and leaving machines in sleep, booting the PC from a powered down condition there seems to be no such problem and again no iMac bios, just a flicker and then up and running with cmd+F2 also working normally

Isn't the 5970 a desktop GPU? You can just stick it in the iMac? And it works with OSX and Windows?

That's like, awesome. I thought the GPU on the iMac wasn't user-replaceable? Is it very difficult?

Sorry to seem annoying, but I never opened up an iMac. Any chance you could post a step-by-step guide with pictures or video? I'm sure many people would appreciate that!

That is using the display input on the 27" iMac. Other card from ATI with DP have driver issues which make it not work. I think it's the 4xxx series. This is important because initial testing made it sem like it was Apple being stupid not allowing non-Apple devices to connect.

Did you have more than one monitor plugged into your card (or another card in your machine hooked up to another monitor) when you use the iMac with your 5970?

That'd be like routing a firehose through a straw. FireWire 800 is designed for hard drives and standard peripherals, while display adapters have to carry uncompressed full-resolution video. (USB 2.0, meanwhile, is less than half as fast as FW800 for continuously streaming content.)

FW800 carries 800 megabits per second (more than enough for hard drives, audio interfaces, and compressed HD video like what you get from most camcorders), while HDMI's maximum bandwidth is 4.9 gigabits per second -- which it needs to carry HD resolutions as high frame rates with enough space left for 8 tracks of HD audio.

Uncompressed 8-bit 1080i video, without audio, has a bit rate of 1.5 gigabits per second. (1080p/24 is 1.2 gigabits, 720p/60 is 1.3 gigabits, and 1080p/60 is a whopping 3.0 gigabits per second.) So the smallest of these standards is still 1.5 times the theoretical bandwidth of FireWire 800.

FireWire is awesome. But if it were usable as a display standard, Apple would have switched to it long ago.

Have 2 monitors hooked up to the one 5970 card besides the iMac 27...below are some configs that are used


using cmd+F2 makes shifting back and forth between the pc and snow easy...CCC senses the change and migrates what was on iMac display from the PC to other displays when that command is given

take a look at steps 21 and 22 to get an idea of the size of the Radeon HD 4670 that is used in the iMac being disassembled
http://www.ifixit.com/Teardown/iMac-...27-Inch/1236/3

....that is the "ATI MOBILITY RADEON HD 4670 ,M96 ,9488"

http://developer.amd.com/gpu_assets/...IDs_Jan_09.txt

now take a look at the 5970 in hand
http://images.google.com/imgres?imgu...HIfSlAfjxri2Aw

wanna try fittin that in the iMac case?

Do you have any problem using the iMac as the displayport monitor if you start up your pc with only the iMac connected and no other monitors connected to yor pc?

support kinda sums up some of the target displaymode stuff but there are some issues with starting up the pc with only the mDP connected to the iMac...the doc says that both machines should be started up and then connect the mDP connections....there might be something to that....

Using a 27-inch iMac as an external display
http://support.apple.com/kb/HT3924

think there will be somewhat different results with different motherboards in how the video card plays with the imac....in process of swapping my p6t out right now and upgrading to another 1366 socket type

I can confirm that the ATI Radeon 5970 using a mini display port to mini display port cable (purchased at the Apple store) attached to the 27-inch iMac with no other monitors connected DOES work with NO problems.

I have a Striker Extreme motherboard in the PC, but doubt really that this has any effect (though who knows).

My summary is that the 27-inch iMac itself ROCKS and is *AWESOME* running Mac OS X as well as as a display. I can also confirm the ATI 5970 is AWESOME.

Christmas is served

congrats
it is no doubt a nice match up the iMac 27" and 5970....now need some games with some beefed up graphics to really enjoy the marriage
having a dell 2407wfphc connected on dvi of card and comparing it with the iMac 27" really shows the depth of difference between the 2 monitor's displays....don't think there is any going backward from here once you have bit the apple 27"...... it is ips all the way

bumping this thread, now that i have my imac in house, and im looking for parts to upgrade my gaming rig, and use the imac as my main display for gaming and stuff. I wanted to know if the radeon 5xxx series (excluding 5970) still doesnt work with the imac display.

Also i come across some good info today about gigabyte h57 motherboards with displayport input. Now i dont know much about comptures. But riddle me this:

Is there a possibility that the gigabyte h57 motherboard paired with the new i5 core 2 duo's is enough to run the imac at its native resolution. Also I can't find any info about the new core 2 duos and the internal gpu that comes with it. And how much resolution they can handle. Any thoughts? I mean most of the radeon cards dont work, but what about this displayport on the motherboard:

Some info about the motherboard here: http://www.ameinfo.com/222523.html

Secondly and this is important (since im not a PC geek). Could u connect the imac to the displayport on the motherboard, and then use a 5870 to give the Computer more juice, or is that not possible since the imac is already using the internal gpu.

Please respond

Best regards

anyone with radeon 57xx or 58xx that wants to tell me if the cards work with the imac with the newest drivers/beta

Well, I can only tell you it still does not work with the Apple Led Cinema Display. This is not because of a driver issue, but a hardware/firmware issue because the display does not turn on when booting. Drivers are not needed until booting Windows.

Hi guys! I'm new here!!!

I just bought a new iMac 27" + radeon 5970... : P

I hope to enjoy soon my iMac also as a main pc monitor! : P