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CaptHenryMorgan

macrumors regular
Original poster
Apr 27, 2013
196
0
The District
Got a 27" 2011 iMac. 3.4Ghz, ATI 6970 with 2GB RAM. Gonna grab this display this week, just curious if anyone knows if the iMac can actually drive it. If not, I'll just wait til the Mac Pro is updated and throw a couple ATI 7000 or nVidia 680s in there and drive it.
 

Tom the MacUser

macrumors member
Mar 26, 2013
31
1
Got a 27" 2011 iMac. 3.4Ghz, ATI 6970 with 2GB RAM. Gonna grab this display this week, just curious if anyone knows if the iMac can actually drive it. If not, I'll just wait til the Mac Pro is updated and throw a couple ATI 7000 or nVidia 680s in there and drive it.
You will be able to drive it at 4K @ 18 Hz for sure - that is as much as is supported by the software. There is a 165 MHz pixel clock limit in the driver.

I made a patch that removes this limit from OS X, but until someone actually tries driving a 4K TV with an iMac with a Mini-DisplayPort to HDMI adapter, I don't know how much above 18 Hz you will be able to get. It works up to 31 Hz from the HDMI port on my 15" rMBP.
 
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omvs

macrumors 6502
May 15, 2011
481
11
FYI: I just hooked up the 39" Seiki to 2011 iMac. Had to use SwitchResX to get the resolution added, but with a little fiddling works fine. As Tom said, it's limited to 18Hz 'stock'.

I accidentally setup a interlaced mode for 3840x2160, and that didn't work at all - display locked to a half-width image, and OSX itself froze. Doh!
 
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iSayuSay

macrumors 68040
Feb 6, 2011
3,435
585
Seiki brand name itself might be shoddy as hell. But they're a good thing to control 4K display tech.

Otherwise the bunch of electronic giants would charge you $3000 on 42" display for the 4K alone. I really really get nauseous by the way they act.

Remember the 3DTV fad? Yeah I'm glad it turned out to be a big fail, and at one point, it was $2000 for 42" just because it has fad technology called "active 3D" and they want $200 for a mere pair of [active 3D glass] alone. Not that it's bad but come on, it's not really that expensive to implement. Fad products deserve to die.
 
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macythecat

macrumors newbie
Jul 20, 2013
1
0
same problem here with the 165mhz clock limit

tried on my macbook pro 15", but only 14Hz, image was not ok on my Skyworth 4k

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even when i say the card can higher than 165hz, it does go higher.
i mailed with the switchres developper and it seems that his software stays in the limits of the driver. so i will need to patch the drivers ?

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same problem as the macbookpro,

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i have also a gtx680 mac edition, same problem as the macbookpro,

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tried with 10.8.4, no help to get higher frequency.... i think i will need a patch.
Maverick should solve this problem, but it seems that the dev downloadservers of apple are down...

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You will be able to drive it at 4K @ 18 Hz for sure - that is as much as is supported by the software. There is a 165 MHz pixel clock limit in the driver.

I made a patch that removes this limit from OS X, but until someone actually tries driving a 4K TV with an iMac with a Mini-DisplayPort to HDMI adapter, I don't know how much above 18 Hz you will be able to get. It works up to 31 Hz from the HDMI port on my 15" rMBP.


what brand of adapter did you use ? i would also like this patch to get my skyworth on 4k
 
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omvs

macrumors 6502
May 15, 2011
481
11
Accell adapter allows 30Hz UHD

I finally got a hold of the Accell Active mDP -> HDMI adapter. With that, I've got my mac mini and iMac pushing out 3840x2160x30Hz. I don't think any patches are necessary (though I had fooled around with Tom's patch at some point - unsuccesfully).

I don't think SwitchResX is even necessary - I have it installed and used to try and go above 30Hz (not yet successful), but the 30Hz showed up without me doing any fiddling.
 
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omvs

macrumors 6502
May 15, 2011
481
11
Sorry for not seeing your reply earlier. Since there's might be broader interest, I figured I'd reply on the thread vs PM:

I'm using the B086B-008B-2 (UltraAV Mini DisplayPort 1.1 to HDMI 1.4 Active Adapter).

http://www.amazon.com/gp/product/B00DOZHL82
http://www.accellcables.com/B086B-008B-2.html

Works great on both the Seiki (3840x2160x30Hz) and my 27" (2560x1440x60Hz). I actually ordered a second one for home, though just realized I screwed up and got the passive version (B086-005B-2). EDIT: The passive version definitely doesn't work - I just tested it, and it has the same 165MHz limitation as all the cheap MDP->HDMI adapters.

Oh, and it does transfer audio if desired... Saw that the other day in the Sound Preferences.
 
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omvs

macrumors 6502
May 15, 2011
481
11
About to go buy the adapter to go do all this on my LG84 - can I watch video at 30HZ?

Should work fine. I tested some 4k video files we got off the web -- it was a little much for the mini's GPU, but iMac has a much better GPU. Non-4k video I'd expect to be perfectly okay.
 
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mrkennethtong

macrumors member
Sep 16, 2013
76
0
Should work fine. I tested some 4k video files we got off the web -- it was a little much for the mini's GPU, but iMac has a much better GPU. Non-4k video I'd expect to be perfectly okay.

Just ordered the exact part you recommended for Amazon one day delivery - shall have it tomorrow! Looking forward to being able to use my rMBP on my LG 84LM9600 - 84 inches of UHD!
 
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mrkennethtong

macrumors member
Sep 16, 2013
76
0
Got it! Amazon next day, ordered last night at midnight, nine hours later, boom!
 

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ariaaria

macrumors newbie
Sep 17, 2013
4
0
Yes just got it as well. BUT.

Ordered the Accell adapter from amazon. Overnighted and got it about an hour ago. But can't get it to work at 30hz. Same setup rMBP, SEIKI 50". Had this working with the Moshi adapter at 14hz. What's the catch, do i need the patch?
 
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mrkennethtong

macrumors member
Sep 16, 2013
76
0
Ordered the Accell adapter from amazon. Overnighted and got it about an hour ago. But can't get it to work at 30hz. Same setup rMBP, SEIKI 50". Had this working with the Moshi adapter at 14hz. What's the catch, do i need the patch?

I am dying here. I just paid $12,000 for the 84 Inch UHD LG and I was hoping this adapter would work. Fail so far, let me know if you work this out!

What are you using for custom resolutions?!
 
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omvs

macrumors 6502
May 15, 2011
481
11
I am dying here. I just paid $12,000 for the 84 Inch UHD LG and I was hoping this adapter would work. Fail so far, let me know if you work this out!

What are you using for custom resolutions?!

Your photo looks like the exact same adapter I have. I didn't even have to add a custom resolution - plugged it in and the 30Hz option showed up (along side the 19Hz I had previously added). What resolution options are you getting?

It could be the EDID on the LG isn't giving out the right data. If you want, I'll get the exact settings for a custom resolution off whats being used with my SE39UY04, but its on my work machine so can't do that until tomorrow.

ariaaria - you got the active adapter, not the passive adapter, right? (see my earlier post for where I screwed that up). Do you still get 14Hz as an option?

Sorry the both of you are having problems. It was very smooth on my side :( With the rMBP, you could use Tom's patch. It just didn't work on either my iMac or my mac mini, so I had to go the adapter route.
 
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unfrostedpoptar

macrumors regular
Jan 29, 2010
173
10
I am dying here. I just paid $12,000 for the 84 Inch UHD LG and I was hoping this adapter would work. Fail so far, let me know if you work this out!

What are you using for custom resolutions?!

Good luck! As I posted on the other 4k thread you're also on, I tried with my rMBP and the Accell adapter with a Sony 55" 4k TV and the computer didn't show 4k as a choice for resolution. Luckily, I did this at a Sony store before buying the TV!

I hope you get this working for your own sake and for the rest of us who want to hook up a 4k TV!

By the way, I noticed the latest Sony and Panasonic 4K TVs all say they'll be upgradable (firmware, I assume) to HDMI 2.0 soon! It would be amazing if the Seiki TVs will do this. I'd imagine the Mac wouldn't have much problem since it's being done through a DP-to-HDMI adapter anyway and DP can handle 4k@60Hz.
 
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ariaaria

macrumors newbie
Sep 17, 2013
4
0
Ut

Your photo looks like the exact same adapter I have. I didn't even have to add a custom resolution - plugged it in and the 30Hz option showed up (along side the 19Hz I had previously added). What resolution options are you getting?

It could be the EDID on the LG isn't giving out the right data. If you want, I'll get the exact settings for a custom resolution off whats being used with my SE39UY04, but its on my work machine so can't do that until tomorrow.

ariaaria - you got the active adapter, not the passive adapter, right? (see my earlier post for where I screwed that up). Do you still get 14Hz as an option?

Sorry the both of you are having problems. It was very smooth on my side :( With the rMBP, you could use Tom's patch. It just didn't work on either my iMac or my mac mini, so I had to go the adapter route.

Yes its the active, so the package label states. The package is exactly the same looking as mrkennethtong.

Yes the 14hz is still working but only with SwitchResX. Without it nothing but 1080p. I'm sure its just a matter of configuration. SwitchResX is a bit buggy for me. I can't seem to get a custom setting to become active. The 14hz setting was kinda lucky after spending hours on it.

mrkennethtong, any luck on your end. I'll send you my 14hz settings tomorrow (laptop is at work)

----------

Your photo looks like the exact same adapter I have. I didn't even have to add a custom resolution - plugged it in and the 30Hz option showed up (along side the 19Hz I had previously added). What resolution options are you getting?

It could be the EDID on the LG isn't giving out the right data. If you want, I'll get the exact settings for a custom resolution off whats being used with my SE39UY04, but its on my work machine so can't do that until tomorrow.

ariaaria - you got the active adapter, not the passive adapter, right? (see my earlier post for where I screwed that up). Do you still get 14Hz as an option?

Sorry the both of you are having problems. It was very smooth on my side :( With the rMBP, you could use Tom's patch. It just didn't work on either my iMac or my mac mini, so I had to go the adapter route.

Good luck! As I posted on the other 4k thread you're also on, I tried with my rMBP and the Accell adapter with a Sony 55" 4k TV and the computer didn't show 4k as a choice for resolution. Luckily, I did this at a Sony store before buying the TV!

I hope you get this working for your own sake and for the rest of us who want to hook up a 4k TV!

By the way, I noticed the latest Sony and Panasonic 4K TVs all say they'll be upgradable (firmware, I assume) to HDMI 2.0 soon! It would be amazing if the Seiki TVs will do this. I'd imagine the Mac wouldn't have much problem since it's being done through a DP-to-HDMI adapter anyway and DP can handle 4k@60Hz.

You know i thought it could be SwitchResX, when you say this worked for you out of the box, do you mean the apple>system preferences>Display settings gave you a the 4k 30hz option? or are you using any other software?
 
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mrkennethtong

macrumors member
Sep 16, 2013
76
0
Thanking everyone for their help thus far, would love your settings tomorrow!

I just don't know what to do; I have the option to return this set but will give it another few days!
 
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omvs

macrumors 6502
May 15, 2011
481
11
So I just borrowed a coworkers rMBP, hooked it up to the Accell adapter & my SE39UY04, and it instantly switched to 3840x2160x30Hz. I doubt he has switchresx loaded or that mode defined, though I'll check with him later.

Assuming you're both running 10.8.4 or 10.8.5 (that's all i've tested on), I'd say it must be an EDID issue. I'll see if I can dig out the proper settings to plug into switchresx to get the right refresh -- I know its a bit tricky because I spent a while trying to get >30Hz, and my set was very fussy.

Also, make sure you save then reboot after adding custom resolutions. When you go back into switchresx after the boot, it should show Status: Active. If it shows invalid, the driver is kicking out the resolution because it thinks its illegal for whatever reason.
 
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Wrambler

macrumors newbie
Sep 18, 2013
1
0
Thanks

I just wanted to thank everyone who has posted here.
While I don't have a 4k I was having issues getting our early 2013 Mac Pro tower with dual 5770 cards to drive both an HP 21.5" 1080P monitor and a Sharp 70" led HDTV on each card.

Under dual boot using bootcamp and Windows 7 the Mac worked fine driving all 4 displays. OS X would just boot randomly to one or two displays.

Switching to the active Accel adapters fixed everything. It even took the 1" border off the dot to dot setting on the HDTV's, which I always wondered why they were there!

I have a couple of Rocketfish adapters that I sure won't be using again!

Thanks again and I'll go away now.
 
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omvs

macrumors 6502
May 15, 2011
481
11
Here's my monitor EDID for 3840x2160x30. This seems to be what I get out of switchResX when using simplified settings and CVT-RB, so I'm hoping its relatively standard.


Monitor Description blocks:
---------------------------
Descriptor #0 - Timing definition:
Mode = 3840 x 2160 @ 30.000Hz
Pixel Clock............. 297.00 MHz Non-Interlaced

Horizontal Vertical
Active.................. 3840 pixels 2160 lines
Front Porch............. 176 pixels 8 lines
Sync Width.............. 88 pixels 10 lines
Back Porch.............. 296 pixels 72 lines
Blanking................ 560 pixels 90 lines
Total................... 4400 pixels 2250 lines
Scan Rate............... 67.500 kHz 30.000 Hz

Image Size.............. 854 mm 481 mm
Border.................. 0 pixels 0 lines

Sync: Digital separate with
* Positive vertical polarity
* Positive horizontal polarity
 
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ariaaria

macrumors newbie
Sep 17, 2013
4
0
Thanking everyone for their help thus far, would love your settings tomorrow!

I just don't know what to do; I have the option to return this set but will give it another few days!

GOT IT! working. So don't give up hope. It was a few oversights on my part.

1. I had SwitchResX installed on my rmbp which was passed its trial period. Even though it explicitly stated that i could continue to use it but could only save 2 custom settings. This turned out to be false or my misunderstanding. Any how, purchased license ($17) and Bam.

2. I continued to have some misfires with saving setting with SwitchResX. The settings would save and would become active after reboot but would not show up on the selection screen. At one point I unplugged the Accell adapter and switched to my older Moshi adapter, the older 3840x2160 14Hz showed up, When I switched back to the Accell adapter the newer custom 3840x2160 30Hz was available to select and worked fine.

So while the Accell adapter did not work for me out of the box, it did work fine after properly registering SwitchResX. Curious if I would have had all these issues if I would have never installed it. I had also installed "Display Menu" app yesterday, which confused everything more. It shows me a completely different list of screen resolutions.

Here is my setup:
rmbp late 2011.
osx 10.8.2
SEIKI 50" 4k tv "SE50UY04"
SwitchResX 4.3.5

29.895Hz Settings:
---------------------------
Mode = 3840 x 2160 @ 29.895Hz
Pixel Clock............. 262.00 MHz Non-Interlaced

Horizontal Vertical
Active.................. 3840 pixels 2160 lines
Front Porch............. 48 pixels 3 lines
Sync Width.............. 32 pixels 5 lines
Back Porch.............. 80 pixels 23 lines
Blanking................ 160 pixels 31 lines
Total................... 4000 pixels 2191 lines
Scan Rate............... 65.500 kHz 29.895 Hz

(unchecked) Positive horizontal sync.
(checked) Positive Vertical sync

13.80Hz Settings:
---------------------------
Mode = 3840 x 2160 @ 13.799Hz
Pixel Clock............. 120.00 MHz Non-Interlaced

Horizontal Vertical
Active.................. 3840 pixels 2160 lines
Front Porch............. 48 pixels 3 lines
Sync Width.............. 32 pixels 5 lines
Back Porch.............. 80 pixels 6 lines
Blanking................ 160 pixels 14 lines
Total................... 4000 pixels 2174 lines
Scan Rate............... 65.500 kHz 13.799 Hz

(unchecked) Positive horizontal sync.
(checked) Positive Vertical sync

And thanks to (omvs)

30.00Hz Settings:
---------------------------
Mode = 3840 x 2160 @ 30.00Hz
Pixel Clock............. 279.00 MHz Non-Interlaced

Horizontal Vertical
Active.................. 3840 pixels 2160 lines
Front Porch............. 176 pixels 8 lines
Sync Width.............. 88 pixels 10 lines
Back Porch.............. 296 pixels 72 lines
Blanking................ 560 pixels 90 lines
Total................... 4400 pixels 2250 lines
Scan Rate............... 67.500 kHz 30.000 Hz

(unchecked) Positive horizontal sync.
(checked) Positive Vertical sync




SIDE NOTE: A few week ago, I also started experimenting with command line tools to add new screen resolutions. Check out http://mac.linux.be/content/setting-xorgconf-manually-xrandr. I know this is a linux how-to but osx has the same tools. Anyhow I was never able to successfully save new Modeline. Everything worked except I could never figure out the name of the external device to save to.
 
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mrkennethtong

macrumors member
Sep 16, 2013
76
0
So I just borrowed a coworkers rMBP, hooked it up to the Accell adapter & my SE39UY04, and it instantly switched to 3840x2160x30Hz. I doubt he has switchresx loaded or that mode defined, though I'll check with him later.

Assuming you're both running 10.8.4 or 10.8.5 (that's all i've tested on), I'd say it must be an EDID issue. I'll see if I can dig out the proper settings to plug into switchresx to get the right refresh -- I know its a bit tricky because I spent a while trying to get >30Hz, and my set was very fussy.

Also, make sure you save then reboot after adding custom resolutions. When you go back into switchresx after the boot, it should show Status: Active. If it shows invalid, the driver is kicking out the resolution because it thinks its illegal for whatever reason.

I got it saying active but can't get it "on" : (
 
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omvs

macrumors 6502
May 15, 2011
481
11
I got it saying active but can't get it "on" : (

Okay, so at least the computer is trying to send out something. I'd guess one of 3 problems:

o The TV is being picky and unable to lock in the custom mode you made. Mine will do anything up to and including 30Hz, but all my attempts to increase beyond that give no image. I noticed ariaaria and my sets have different EDID values for 3840x2160 despite being from the same manufacturer. You might try dumping the EDID data from yours to see what it says

o You cable can't handle is distorting the signal too much - I'd try grabbing another high speed cable and see if it works any better. If its borderline, it could fail with no image at high resolutions rather than giving a flakey image

I'm using a rather thick one that came with the Seiki -- haven't fooled around very much with other cables for that res. But I do have a hdmi cable that has trouble even with 1080p, and when I accidentally try and use it I spend 10-15 minutes trying to figure out why nothing works. Really should throw that one away....

o Bad adapter / bad tv? I'm going to assume the laptop is probably good since you have two thunderbolt ports to chose from and the odds of being flakey should be small.
 
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