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Hi folks. I am not a hardware nerd at heart. It appears this 'iris' GPU will not be able to do 4k display. Does anyone confirm?

frandroid 12y ago
It better be able to do 5K, since the Thunderbolt will inevitably be upgraded to the same screen the new Retina iMac comes with...
- alexgaribay 12y ago
  It won't because the bandwidth of TB2 cannot transfer the amount of data needed for a 5K display. The new Retina iMacs can get away with it because it can interface with the graphics output directly.
  - gambiting 12y ago
    Hmmmm my math can be wrong but I don't think you are correct: 5120x2880 = 14745600 pixels 14745600pixels x 3 colours, 1 byte each = 44236800 bytes 44236800/1024/1024 = 42.19MB each frame 42.19MB per frame x 60 frames a second = 2531.25MB. TB2 has a bandwidth of 20Gbps = 2560MB/s So yeah, theoretically TB2 has enough bandwidth. But it's a very tight fit.
    - Shebanator 12y ago
      I don't know the actual answer, but it may be that the display actually expects 32bpp, in which case it would be over the limit by a considerable amount.
      - nullz 12y ago
        The above calculation was for 32bpp: 3 colors * 1 byte * (8 bits/byte) = 32 bits
        gambiting 12y ago
        I am sorry,but no it wasn't. 3*8 is 24 not 32. But in any case I don't think the display requires 32 bits, alpha is not necessary.
        Shebanator 12y ago
        Thanks for the clarification. fwiw, I knew that alpha wasn't necessary, but vaguely remembered that DisplayPort might support displays that expected the entire 32 bit word to be sent. Looking at the specs, I don't see that. But it does show that DisplayPort supports 16 bits per component, or 48bpp. FYI, Wikipedia's section on DisplayPort lists the resolution of 5120x2880 x 24bpp @ 60Hz as requiring 22.18 Gb/sec of bandwidth, see http://en.wikipedia.org/wiki/DisplayPort#Specifications http://en.wikipedia.org/wiki/DisplayPort#Specifications
    - brigade 12y ago
      Displayport (and HDMI) have a 2 bit ECC overhead for every 8 bits transmitted, so effective bandwidth of DP 1.2 is 17.28 Gbit/s. Additionally, the timing adds additional overhead, so the required bandwidth is actually 22.18 Gbit/s for 24bpp 60Hz 5120x2880
- MHordecki 12y ago
  Even if the GPU does, DisplayPort 1.2 doesn't support 5K displays.
zador 12y ago
According to Intel site, looks like it can do 4k.
UVB-76 12y ago
Tech specs suggest both the Intel Iris and Intel HD Graphics 5000 models have the same support for 4K: https://www.apple.com/mac-mini/specs/ https://www.apple.com/mac-mini/specs/
Xeoncross 12y ago
The HDMI has "Support for 4096-by-2160 resolution at 24Hz" - http://store.apple.com/us/buy-mac/mac-mini http://store.apple.com/us/buy-mac/mac-mini Still only 1080p at 60Hz
MHordecki 12y ago
Iris (such like the one in 13" rMBP) can't, Iris Pro (15" rMBP) can.

frandroid 12y ago

It better be able to do 5K, since the Thunderbolt will inevitably be upgraded to the same screen the new Retina iMac comes with...

alexgaribay 12y ago
It won't because the bandwidth of TB2 cannot transfer the amount of data needed for a 5K display. The new Retina iMacs can get away with it because it can interface with the graphics output directly.
- gambiting 12y ago
  Hmmmm my math can be wrong but I don't think you are correct: 5120x2880 = 14745600 pixels 14745600pixels x 3 colours, 1 byte each = 44236800 bytes 44236800/1024/1024 = 42.19MB each frame 42.19MB per frame x 60 frames a second = 2531.25MB. TB2 has a bandwidth of 20Gbps = 2560MB/s So yeah, theoretically TB2 has enough bandwidth. But it's a very tight fit.
  - Shebanator 12y ago
    I don't know the actual answer, but it may be that the display actually expects 32bpp, in which case it would be over the limit by a considerable amount.
    - nullz 12y ago
      The above calculation was for 32bpp: 3 colors * 1 byte * (8 bits/byte) = 32 bits
      - gambiting 12y ago
        I am sorry,but no it wasn't. 3*8 is 24 not 32. But in any case I don't think the display requires 32 bits, alpha is not necessary.
        Shebanator 12y ago
        Thanks for the clarification. fwiw, I knew that alpha wasn't necessary, but vaguely remembered that DisplayPort might support displays that expected the entire 32 bit word to be sent. Looking at the specs, I don't see that. But it does show that DisplayPort supports 16 bits per component, or 48bpp. FYI, Wikipedia's section on DisplayPort lists the resolution of 5120x2880 x 24bpp @ 60Hz as requiring 22.18 Gb/sec of bandwidth, see http://en.wikipedia.org/wiki/DisplayPort#Specifications http://en.wikipedia.org/wiki/DisplayPort#Specifications
  - brigade 12y ago
    Displayport (and HDMI) have a 2 bit ECC overhead for every 8 bits transmitted, so effective bandwidth of DP 1.2 is 17.28 Gbit/s. Additionally, the timing adds additional overhead, so the required bandwidth is actually 22.18 Gbit/s for 24bpp 60Hz 5120x2880
MHordecki 12y ago
Even if the GPU does, DisplayPort 1.2 doesn't support 5K displays.

zador 12y ago

According to Intel site, looks like it can do 4k.

UVB-76 12y ago

Tech specs suggest both the Intel Iris and Intel HD Graphics 5000 models have the same support for 4K: https://www.apple.com/mac-mini/specs/ https://www.apple.com/mac-mini/specs/

Xeoncross 12y ago

The HDMI has "Support for 4096-by-2160 resolution at 24Hz" - http://store.apple.com/us/buy-mac/mac-mini http://store.apple.com/us/buy-mac/mac-mini Still only 1080p at 60Hz

MHordecki 12y ago

Iris (such like the one in 13" rMBP) can't, Iris Pro (15" rMBP) can.