Banding on my new mac mini

[janlewis]

Hi, I just bought a new mac mini from Apple and my gradients are banding in photoshop. I don't think it's the monitor as I've swapped screens and it's the same on both. I don't think it's photoshop as it works fine on my old mac.

The new mac is a mac mini (late 2014 but it is brand new). 2.6GHz Intel Core i5 with 8gb memory. Graphics: Intel Iris 1536 running Sierra 10.12.6

My previous mac (which is fine) is a mac mini (mid 2010). 2.4 Intel core duo with 16gb memory. Graphics: Nvidia GeFoce 320M 250MB running ElCapitan 10.11.6

Have I made a mistake buying a new mac? Am I missing something, some settings I need to change to use photoshop to it's best capacity?

I'd appreciate any feedback from you wonderful tech-heads.
Jan

 

[Fishrrman]

What kind of monitor?
What kind of connection?

 

[janlewis]

What kind of monitor?
What kind of connection?

Monitors - a (refurbed) 23" apple HD cinema display (doesnt band with the older mac mini) and a new AOC 27" U2777pqu 4k both connected by HDMI.

 

[Fishrrman]

Do you get banding with the AOC display, as well?

 

[janlewis]

Do you get banding with the AOC display, as well?

Yes - that was where I first noticed it. If it's not anything obvious, there's something else I could try. I dont like the AOC so I'm swapping it for a new 27"LG so I could just wait and try that when I get it.

 

[treekram]

Are you running the same version of the OS and Photoshop on both computers? If not, it may be due to a version difference in the OS or Photoshop.

The 2014 Mini has the Intel Iris 5100 GPU (1536 is the amount of VRAM). It's capable of 24-bit color (8 bits per color channel) with a 8-bit alpha channel. So in the System Report, you'll see that it is "32-Bit Color". From the specs that I've seen of the Nvidia GeForce 320M, it also has 8 bits per color channel. Again, from specs that I've seen of the 30" HD Cinema Display, it is 8-bit color, the AOC is 10-bit color. In order to get 10-bit color, both the display and computer have to be able to do 10-bit color. There's various test jpeg's on the Internet to test banding and I used one of these because one of my computers does have 10-bit color but I only have 8-bit displays so I see banding on the test jpeg I downloaded. Because of the hardware you tested, I don't think you would have banding due to the hardware 8 bit vs. 10 bit issue. Another way that is used to describe the number of color bits supported is the number of colors supported - 8 bit is over 16 million colors, 10 bit is over 1 billion colors. It may be that the 320M does something to better dither color gradients - I don't know. However, if you really need 10-bit color, you should return the Mini if you can because it doesn't have that support.

 

[janlewis]

The OS on the older mini is older. Photoshop is the same (latest CC). I don't think I need 10 bit as the older mini was fine. I think the new mini isn't a great improvement on the old but it can't actually be worse can it? If the graphics card isn't as good, I will consider returning it but I will investigate further. Can you share a link to the banding tests you found? Thank you both @Fishrrman and @treekram for your time.

 

[for this]

There are many complaints about Sierra (and High Sierra) not working properly with external displays. This one is similar to yours.
https://discussions.apple.com/thread/7690725

Being under a bit of bad mood about the Apple's neglect, may I say this problem can be easily fixed by stopping using any external display altogether since Apple don't bother support it any longer

 

[Boyd01]

I still have my 23" Apple Cinema display that I bought new somewhere around 2005 IIRC. Have never seen a problem like you describe using it with two 2012 Minis or a 2013 MacBook Air on Mountain Lion or Sierra. My 2014 Mini is an iTunes server connected to a 720p screen and I never use it for anything like Photoshop, so I don't know what problems it might have.

 

[treekram]

The OS on the older mini is older. Photoshop is the same (latest CC). I don't think I need 10 bit as the older mini was fine. I think the new mini isn't a great improvement on the old but it can't actually be worse can it? If the graphics card isn't as good, I will consider returning it but I will investigate further. Can you share a link to the banding tests you found? Thank you both @Fishrrman and @treekram for your time.

If you search for "10 bit color depth test" or "image banding test", there will be a lot of results. Right now, I can't find the link to the site where I downloaded the test image I have but I can upload what I downloaded it and hopefully the creator of the file won't be unhappy with me. (If somebody has a 10-bit color computer and display, if you can confirm this doesn't band, it would be appreciated. I have a 10-bit color computer but not a display. No Mini's have 10-bit color - unless I misinterpreted the specs for the more recent Mini's that had dGPU's.)

In looking at the sites, you have to be careful because they may have modified the image to make a point. So, in order to show what banding looks like, they'll have an image that will show banding if you have 8 bit or 10 bit. You have to look specifically for test images that can be downloaded that will band at 8 bit but not at 10 bit. You should try it using something like the Preview app and with Photoshop. It's tricky to look at the videos that will come up in the search results because that adds a layer of additional variables to consider.

 

[A Hobo]

23” Apple display, connected via HDMI.
I’m missing some crucial info here.

 

[janlewis]

Thanks everyone for your help. I solved this the lazy non-techy way. I returned the AOC and now have a 27"LG Ultra HD Display as recommended by a colleague. It's perfect (and £150 less!).