Indeed, AMD is behaving in an ***** fashion as of late. First the power supply issue with the RX 480, then repeated issues with the Crimson drivers. They just need to mess it up with Zen , and thta's a hat trick :-(
However, the fan throttling issue is not really new, and unless I'm mistaken was already considered as dealt with by Crimson 15.12. Or is it making a comeback now ?

If you have and RX 480 and using crimson driver 16.7.3 you may want to revert back to old driver. Any OCed 480 is broken with that driver.

You can see it here. https://www.youtube.com/watch?v=Ekdte9UoGyE

Whenever you install new AMD drivers is highly recommended that you uninstall the old drivers and Vulkan run time libraries first. Don't update over the old.

I would suggest you use Display driver uninstaller next and then install newer drivers.

http://www.guru3d.com/files-details/display-driver-uninstaller-download.html

Lastly use Ccleaner to remove any left overs in your registry.

unlike Nvidia drivers AMD drivers are not as good and require abit more maintenance by pc owners.

Yeah, nVidia never have power bugs or recurring issues.

I've been a Nvidia fan for a long time. 6 years ago nvidia released a driver that prevented stock fans adjusting to the heat of the cards to keep them cool. Many nvidia users lost there cards. Fortunate for me I managed to get a replacement after 2 months and moving up the support ladder. That card was out of warranty as well. I switched to ATI and found out they're issues over time. Nvidia drivers tend to be more solid than ATI. Hardware ATI cards are better than nvidia. Games devs support nvidia so games run better on those gaming platforms that support nvidia no matter how good ATI hardware is or how well optimized the drivers are.

All in all EndlessWaves, I don't care for Nvidia or ATI fanboyism All I care is for what works. If nvidia has a card that works flawless and gives me what I want like the new GTX1080 then I'll buy it. ATM I'm using R9 290x and I love it. Once the warranty runs out I'll hex edit the firmware and make it look like a R9 390x. :P I invest in what works not because of how its called. I've provided information on how I've experienced both products over the many long years. Take the free information or leave it. ;)

In my experience, you trade one batch of problems for a different batch of problems when it comes to nvidia or amd.

If the problem is resolved by going 100% on the fans, then it most definitely is a heating issue.

In addition to turning up the fans, you can also try to reduce the load on the gpu. Makes sure that you have vsync on if it is not. Also, try reducing options like shading and any AA, which I doubt you have set it very high with a 280x. Also, lower resolution with vsync on is another way to lessen the gpu load.

Thanxs for all the info guys . Ill roll back the drivers later on today and see if it makes any diffrece. also i never normally clean my gpu drivers when new ones come out could be the problem. Probally worth checking out.