So it seems Apple has included an unexpected present in Sierra: For the first time since HD 7xxx era they've included a framebuffer personality matching a standard PC PCIE card!

I've already seen a framebuffer dump from AMD9500Controller online, but it seemed to be corrupted, had a strange structure. When looking closely, I realized that they had changed the structure form 16 bytes per connector to 24 bytes. So, with a simple modification to the framebuffer dump tool I got this:

Exmoor (6) @ 0x1cf6c0

LVDS, LVDS, DP, DP, DP, DP

020000000001000000010151000000002205020400000000

020000000001000000010261010000001204010300000000

000400000403000000010343000000001102030100000000

000400000001000000010431000000002103050500000000

000400000403000000010523000000001000040200000000

000400000001000000010611000000002001050500000000

Berbice (5) @ 0x1cf750

LVDS, DP, DP, DP, DP

020000000001000039050108000000002001010100000000

000400000001000000010233000000001000020200000000

000400000403000000010313000000002103030300000000

000400000403000000010453000000001102040400000000

000400000403000000010533000000001204050500000000

Acre (3) @ 0x1cf830

DP, HDMI, DDVI

000400000403000000010101000000001102020100000000

000800000402000000010200000000002103050400000000

040000000402000000010300000000000000030500000000

Caroni (5) @ 0x1cf8f0

LVDS, LVDS, DP, DP, DP

020000000001000000010141000000001102020400000000

020000000001000000010231010000002103010300000000

000400000403000000010303000000002001030100000000

000400000403000000010403000000001204040200000000

000400000403000000010501000000001000050500000000

Florin (6) @ 0x1cf9d0

LVDS, LVDS, DP, DP, DP, DP

020000000001000000010141000000001102020400000000

020000000001000000010231010000002103010300000000

000400000403000000010313000000002001030100000000

000400000403000000010421000000001000050500000000

000400000403000000010553000000002205040200000000

000400000403000000010661000000001204060600000000

Dayman (6) @ 0x1cfa80

DP, DP, DP, HDMI, DDVI, DP

000400000403000000010101000000001204060100000000

000400000403000000010201000000002205040300000000

000400000403000000010301000000001102010200000000

000800000402000000010400000000002103050400000000

040000000402000000010500000000000000030600000000

000400000001000000010601000000002001020500000000

Baladi (6) @ 0x1cfb30

DP, DP, DP, DP, DP, DP

000400000403000000010300000000001204030300000000

000400000403000000010100000000001102010100000000

000400000403000000010200000000002103020200000000

000400000403000000010400000000002205040400000000

000400000403000000010500000000001000050500000000

000400000403000000010600000000002001060600000000

OPM (5) @ 0x1cfbc0

DP, DP, DP, DP, DP

000400000403000000000001000000001102020200000000

000400000403000000000001000000002103030300000000

000400000403000000000001000000001204010100000000

000400000403000000000001000000001000040400000000

000400000403000000000001000000002001050500000000

Right in the middle you'll find "Dayman", which offers 4 DP, 1 HDMI and 1 DDVI: A combination I wouldn't expect on any Mac today.

So I went ahead, grabbed a freshly uploaded RX 480 ROM from Techpowerup, ran the well known dump tools and got this:

**DP1:** 0x12 / 0x4 / 0x6 / 0x1

**DP2:** 0x22 / 0x5 / 0x4 / 0x3

**DP3:** 0x11 / 0x2 / 0x1 / 0x2

**HDMI:** 0x21 / 0x3 / 0x5 / 0x4

Yep, that's a 100% match with Dayman!

I guess Apple made that Dayman FB for an internally tested prototype: On the publicly available RX 480's you still can see the soldering pads for a DDVI connector, and Apples prototype might also have had an additional DP.

Anyway, I think we might finally be looking forward a properly supported AMD card, which can achieve 100% functionality.

It has already been shown that AMD9500Controller will pick it up & initialize it properly, only thing missing is the device ID in X4000.kext to enable acceleration:

http://forums.macrumors.com/threads/amd-confirms-rx-480-at-199-usd-other-apu-polaris-announcements.1975249/page-6#post-23067345