Originally Posted by CallsignVega
I wonder if Sapphire was betting on the mythical MST Hub that is vaporware. Here is some interesting information on that front:
I wonder if it having two Displayport's if you could run two MST Hubs at the same time. Not entirely positive, but it looks like DP 1.2 with a MST Hub should just be able to run two 1080P monitors at 120 Hz. It all comes down to the MST Hubs with this card fro proper Eyefinity. But then again, the 89xx series may very well be out before we see those.
Except that 8x MSAA is pretty much pointless.
AMD has been betting on these HUB's since 2010 when they released 6xxx series but apparently there is some technical problems with these. The first models were scrapped bcos of somekind of hardware bug which meant that the hubs were not able to work with hot plugging and you had to connect displays in very specific order for them to work. Last CES had still the similar prototypes shown that remain to go properly through miniaturization and I have seen claims that these hubs should at last release 2012 "summer" but tbh I will not hold my breath over it.
If you read the AMD blog they are linking in that thread then the last comment in there from the 2nd July is from me lamenting about the hub remaining vaporware and suggesting them to do next series just with display ports.
As far as bandwidth goes DP 1.2 is 17.28 Gbit/s on 2m cable and 1920 × 1080 × 24 bpp @ 60 Hz (that is 6 bit color) is as low as 3.33 Gbit/s (without the overhead needed for CRT, i.e., on LCD screen) so you can indeed drive two of these @ 120 Hz through DP 1.2. At higer resolutions you can do 2560 × 1600 × 30 bpp @ 60 Hz which is 8.06 Gbit/s, i.e., 2 screens per displayport, or you can do one @120Hz on 2m cable. You can even do 3840 × 2160 × 30 bpp @ 60 Hz (thats 4k) which is about 16 Gbit/s.
DP 1.1a has half the bandwidth of DP 1.2 and does not support multi stream and daisy chaining. DP 1.2 standard was confirmed 2009 December and AMD jumped on bandwagon shortly thereafter with 6xxx series cards betting heavy on DP 1.2 displays and hubs being available soon after the series release.