Help with identifying graphics card & 4K support in AIW PC

[SILVR 6]

I have an Asus ET2702 with a Radeon HD8890A 2GB I'm trying to figure out whether or not it can support 4K displays at 60hz or not.

http://www.asus.com/AllinOne_PCs/ET2702IGTH/

GPU-Z Screenshot

From my searches online there is nothing mentioned about a Radeon HD8890A 2GB other than on Asus' website talking about this model.

It has HDMI out (which does 2560x1440 Running my 1 of my P278Q) Also has 2 Thunderbolt ports which run my 2 P278Q monitors.

I'm looking to replace all these monitors with ideally 2 4K displays, either the Asus PB287Q or the Samsung U28D590D

Here's what I can gather from looking online about my GPU

It appears to closely resemble a HD8870M with the expetions that it is clocked much higher at 925mhz vs the 725mhz of the 8870m

http://www.notebookcheck.net/AMD-Radeon-HD-8870M.86798.0.html

Found this data sheet from Amd.

http://www.amd.com/Documents/AMD-Radeon-HD-8000M-Series-GPU-Specs.pdf

I'm guessing the HDMI port will run a monitor at 30hz which isn't ideal, but my real question is the Thunderbolt ports. As I have run monitors off them and use of the the TB ports as my main display to play some games with no issue.

According to the datasheet the gpu supports DP1.2 which means 4K at 60hz but TB ports from my reading only will support at 30Hz. So without dropping the money on the monitors to find out, any ideas if this is even doable.

The reason I think it "May" work is because currently when I have my monitors attached to the TB ports one of those is my main screen and plays games fine meaning it might be running through the Amd GPU, the HD4600 in the 4770 does not show up anywhere in the device manager and I believe its disabled through the bios.

Thanks

 

[Armenius]

If it has Thunderbolt 2 ports (20 Gbps), they should have enough bandwidth to output 4k @ 60 Hz (~12 Gbps w/ 8-bit colour, ~15 Gbps w/ 10-bit colour). It really comes down to if the monitor support 4k @ 60 Hz over Thunderbolt 2, though. According to the spec sheet you linked the ET2702 does not have any Displayport outputs.

 

[SILVR 6]

That is correct however I'm running 2 monitors off the 2 thunderbolt ports via display port at 2560x1440 without issues. I know I don't have thunderbolt 2 but thunderbolt has the same connection as mini display port.

 

[Quartz-1]

It's not the connector but the bandwidth. You need TB 2.