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Level 1

8 points

ATI Radeon HD 4870 and 10-bit Color

I recently purchased a used ATI Radeon HD 4870 graphics card ( Apple model # - MB999ZM/A) to install in my early-2008 Mac Pro. This card was originally offered by Apple as an upgrade for earlier Mac Pros. The card has a mini display port (and a DVI-D port). I am running El Capitan on my Mac Pro. I have a 10-bit color capable NEC PA 302W monitor. Can anyone tell me if the ATI HD 4870 card will support 10-bit color to my monitor? I was encouraged to learn from the forum that the drivers (and hopefully their updates) for supported graphics cards are automatically included in the Mac operating systems. I'd appreciate any help anyone can give me. The card is scheduled to be delivered next week. Thanks a lot, Jack

Posted on Dec 4, 2015 12:53 PM

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Grant Bennet-Alder

Level 10

127,903 points

Posted on Dec 4, 2015 5:06 PM

Apple has changed this within El Capitan. According to Mac & I, Apple has confirmed that the new 5K and 4K iMac (along with the 2014 iMac 5K) support a 10-bit graphics driver which has been enabled with the release of El Capitan.

First, apparently it only works on the 4K & 5K iMac 2015 & 5K iMac 2014 right now.[UPDATE]: A cinema5D reader reported that he got 10 bit on a Mac Pro with D500 graphics and an Eizo CS230 monitor.

Also, currently it only works within the Preview and Photos applications. If you want to test it out, you could take a 12-bit RAW photo with soft color gradations and take a look. But it’s also important to note that, for now, no other apps, such as Adobe or other editing software, take advantage of this processing, yet. This is just a preview of what’s to come.

from:

https://www.cinema5d.com/5k-imac-10-bit-color/

So it looks like it is just being introduced now. When/whether 4870 supports it is anyone's guess.

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41 replies

jh191 Author

Level 1

8 points

Dec 12, 2015 3:41 PM in response to John Lockwood

I've used that download before, but I just did a fresh download again. I'm attaching 2 photos I just took of screen with my admittedly so-so iPhone 5 camera. The ramp looked quite smooth opened in Preview. It shows a little banding opened in PS CS5. The photos represent accurately what I'm seeing on my screen. Not sure what the cut-off point is for banding..? Is no visible banding AT ALL the standard..?, or can one see some banding, and still be in 10-bit color? The top image is opened in Preview. Bottom in PS CS5.

Dec 12, 2015 5:01 PM in response to jh191

PhotoShop CS5 definitely does not do 10-bit. It needs to be completely smooth any banding would mean it is not 10-bit. Unfortunately I and most people will be viewing your photos on none 10-bit displays so it will be impossible to judge.

It is apparently possible to download a trial copy of PhotoShop CC.

jh191 Author

Level 1

8 points

Dec 12, 2015 5:36 PM in response to John Lockwood

That's exactly what I was trying to determine yesterday, namely can Mac versions of CS5, or CS6 function in El Capitan with a suitable system or hardware?

I started a thread on the question in the Adobe forum, and was advised by a Staff person there that my long ago installed Mac version of CS5 would now be able to operate in 10-bit color , if I went to- Photoshop > Preferences > Performance, and in the pane section marked GPU Settings made sure the box labeled Enable OpenGL Drawing is checked, and then clicked the Advanced tab, and selected Advanced. I was wondering about this ,because I thought I remembered seeing another article that said only PS CC for Mac was able to operate in 10-bit color in El Capitan. Here's the link to the Adobe thread -10-Bit Color Depth in PS CS5?, CS6?, CC? in El ... | Adobe Community

jh191 Author

Level 1

8 points

Dec 12, 2015 6:14 PM in response to jh191

Make that ...can Mac Versions of CS5, or CS6 function in El Capitan in ten -bit color mode with a suitable system or hardware?

jh191 Author

Level 1

8 points

Dec 13, 2015 2:13 AM in response to jh191

Hello All, I just did the following test. I used the test ramp below from the article John Lockwood gave the link to earlier. I opened the test ramp from my Finder in Preview after selecting "Millions of Colors" in the SwitchResX menu [ my system report then showed 32-Bit Color (ARGB8888)]. The opened test ramp showed clear and distinct banding. I then closed the file, and selected "Billions of Colors" in the SwitchResX menu [my system report then showed 30-Bit Color (ARGB2101010)]. I opened the test ramp again in Preview from my Finder. This time it was completely smooth! Not the slightest trace of banding! Here's a link to the test ramp used

10 bit test ramp.zip (1,222,958 bytes

I'll add the same test ramp opened in my old for-Mac PS CS5 did show banding even when "Billions of Colors" was selected in the SwitchResXMenu.

This all indicates to me that I am in 10-bit color in El Capitan 10.11.2 when I have selected "Billions of Colors" in the SwitchResX menu, and that my CS5 is not operating in 10-bit mode even when 10-bit color is enabled in my OSX.

jh191 Author

Level 1

8 points

Dec 14, 2015 3:50 PM in response to jh191

Okay. Back again after installing a trial version of PS CC for Mac, I opened the same test ramp file from my previous post from my Finder in CC with"Billions of Colors" selected in the SwitchResX menu, 30-Bit Color (ARGB2101010) showing in system report. The opened file was completely smooth- no banding. Then closed the file, selected "Millions of Colors" in SwitchResX menu, 32-Bit Color (ARGB8888) showed in system report, opened the same ramp file from my Finder again, but the ramp still looked completely smooth! I then closed the file, and un-clicked 30 Bit Display in PS CC's Advanced Graphics Processor Pane. With 30 Bit Display un-clicked in that pane the same test ramp showed clear and distinct banding in CC whether I had "Billions", or "Millions of Colors selected in Switch ResX , or what the Mac system report showed , prior to opening it. Makes me wonder if the "30-bit color " in CC for Mac is for real, or the result of dithering, as some have suggested.-

Support for 30-bit display output

Photoshop is able to support 30-bit displays (10-bits per channel) for improved bit-depth viewing, provided that the monitor hardware, the graphic card and operating system,
all support 30-bit. If so, Photoshop can render the video data into 30-bit buffers. The latest Windows operating systems are capable of supporting this fully. It is claimed that the latest Mac OS X systems can do so too, though what the Mac operating system actually does is to dither the 30-bit video output to 24-bit (which isn’t true 30-bit, but something slightly better than 24-bit). It is therefore so far only Windows users who can really take advantage of this feature.

The paragraph above is from the following piece - (no title) . There's no date (or author's name) given. There are references to 2015 in the piece, but I don't know when the section above was written. I have heard others say that the Mac Version PS CC's 10-bit color is not true 10-bit color, but is the result of dithering. Windows versions of CC have true 10-bit color evidently. Perhaps dithering explains my results in CC. Once again, as I related in my previous post the test ramp opened in Preview with SwitchResX "Billions of Colors" selected was smooth, but when opened in Preview with "Millions of Colors" selected was distinctly banded.

jh191 Author

Level 1

8 points

Dec 15, 2015 8:47 AM in response to jh191

I did some screen captures of the same test ramp opened in CC last night. The one with the more distinct banding was opened from Finder with CC's Preferences > Performance then "Use Graphics Processor" unchecked (effectively disabling "30Bit Display"), I then closed the file , checked "Use Graphics Processor" and re-opened the file , and got the smoother one (thought it was completely smooth, but looking at it at different zoom levels, or smaller on my screen, can see some banding) .

jh191 Author

Level 1

8 points

Dec 16, 2015 4:01 PM in response to jh191

Three more screen captures of the same test ramp opened in trial version PS CC (20151114.r.301x640) in El Capitan 11.10.2. with "Use Graphics Processor" (and "30 Bit Display") selected in CC's preferences > performance. The first shows the ramp at 100% looking smooth, the second at 64% still looking smooth, the third at 63% suddenly showing banding and a thin (one-pixel?) border around it. The ramp also showed banding at zoom levels below 63%. That 64% zoom-level cut-off point , and one pixel border were reported on by two others on page 2 of the following Adobe forum. -PS cc and 30 bit | Adobe Community

As mentioned in a previous post the same test ramp open in CC with "Use Graphics Processor" un-selected exhibited banding at 100% , and all zoom levels (from roughly 25%-200%) that I looked at. No one-pixel border appeared at any zoom level.

Apr 17, 2016 4:46 AM in response to jh191

Hi everyone,

I have an early 2008 mac pro running 10.11.3 with a 7950 on DisplayPort. I installed SwitchResX and activated 'Billions of colors' options. I still can't see my mac displaying a 10-bit output nor I can see a fine gradation in the ramp test in Photoshop CC - in which I cannot see the 10-bit option. My monitor is a Philips 241P6V, which is 8+2 bits (not real 10-bit), and I don't know If I still should be able to see El Capitan displaying 30-bits on System Report or not.

Any help would be very much appreciate, I work as a photographer and I would love to have photoshop in 10-bit mode.

Thanks all, this is being really really helpful.

Cheers,

Fran

Apr 17, 2016 5:03 AM in response to hornet330

I have a Mac Pro 2010 running 10.11.4 with a HD 7950. I also have tried SwitchResX and via it was able to activate 30bit mode such that it showed up in System Report. However I can categorically say that it does not work for real as my Sony TV still did not show it was detecting 10bit mode. The same Mac, video card, cable and TV do get detected as 10bit mode when used in Windows 10 via Boot Camp.

Therefore I do not believe SwitchResX is really able to enable 10bit mode despite what is shown and claimed.

Note: I am using the HDMI connection.

I have been reporting this as a bug to Apple and suggest you do so as well. Sadly this is not the only case of Apple artificially crippling video card capabilities on the classic Mac Pro. 😟

I don't have a problem with Apple not providing features on older Macs where there is a genuine technical reason e.g. AirPlay mirroring not being supported on the classic Mac. But I totally object when the hardware is proven to be able to do things e.g. in Windows on the very same Mac and therefore OS X is artificially crippling things. It merely makes OS X and Apple look stupid. (Apple's implementation of AirPlay mirroring is dependent on an Intel chip feature which the old Xeon chip in the classic Mac Pro does not support.)

Apr 17, 2016 11:30 AM in response to John Lockwood

Hi John,

after a reboot my mac displays the 2101010 and I am now able to see a super smooth gradation on the sample test in Preview. I am not NOT able to see the image that way in Photoshop (neither CC2014 nor CC2015) though. I looked a hundred times for that option inside Prefereces > Performances but the menu does not display any 30bit mode. Don't really know what to do here.

ATI Radeon HD 4870 and 10-bit Color