PC Graphics

[yosifov]

I want to know what is the maximum supported resolution for my video to connect it to external display.

[elstaci]

Since you didn't mention an exact HD 5xxx series GPU model. Here is the Radeon HD 5870 specs from CNET. This GPU card is considered to be Mid-Range GPU Card: ATI Radeon HD 5870 - graphics card - Radeon HD 5870 - 1 GB Specs - CNET 

It is a good bet this resolution is similar to most HD 5xxx series GPU cards. But depending on the manufacturer and GPU Model it may vary.

EDIT: Reread your question and you mentioned MOBILE HD 5xxx series GPU. Found this website that mentions the same maximum resolution as the regular HD 5870 GPU Card: https://www.game-debate.com/hardware/index.php?gid=367&graphics=Mobility%20Radeon%20HD%205870 

[yosifov]

Thanks for the answer. The interesting thing is that I actually can't find the exact model of my video. Every tool that I use displays the series name but I guess the maximum resolution will be the same as the model you mentioned. Thanks again.

[elstaci]

Have you tried GPU-Z?

Also if you have a laptop, the exact Laptop model under Specs should mention the exact AMD GPU you have installed.

[yosifov]

Yes, GPU-Z returns only series:   

The information what I've got from the manufacturer of my laptop by service tag is:   

[elstaci · Accepted solution]

according to GPU-Z Device ID: 1002-68E0 you have a HD 54xx GPU card installed as per this website:

Found Specs on that the ATI MOBILITY HD 5470, which is probably what you have installed in your laptop:

[yosifov]

Now, thinking about it, I think it was 5450 but I assume that it will have the same specs as 5470. Thanks again for the help and research! Helped me a lot