FFXIV & R9 290X Troubles

[Morgwyn]

Create a new windows user account (administrator account) and try to play from there.

However since you mentioned you installed two OS, it means this probably won't work.

The other things i can think off are the Power Supply and BIOS settings.

Did you install just the GPU, Auido and Chipset/SATA drivers or did you install the whole drivers thing? Can be an issue with another driver, updated drivers don't always mean stable under some configs.

No, not two OS at the same time (clean installation - formatted entire drive)
My user account is an administrator account.

• I tried the whole driver-set from AMD main page (beta, current and previous) also the set from Sapphire main page (current, previous);
• The single graphics-driver from AMD (beta, current and previous) and Sapphire (current and previous, sapphire offers no betas) both with the standard drivers from windows
• Then the graphics-driver from AMD (beta, current, previous) and Sapphire (current, previous) with chipset-drivers from AMD (beta, current, previous) and Gigabyte (only found current and seems to be the same like AMDs)
• and so on...

And the same Scenario with different BIOS versions (beta, current, previous)

I used a Recovery Image i made from a new and "clean" win8.1Pro-Installation otherwise I would have gone insane of uninstalling and perhaps producing further sources of error.

I really did not test all these things again with win7, three hours updating are not funny I only tried with beta & current driver-versions.

Benchmarks (FurMark, 3DMark) worked all the time also other games I've tried!
The newer the driver-versions the better were the results.

Only FFXIV told me "No Way!"
Yes, I had to reactivate my SquEx Account a lot of times because you get restricted if you try to log in on every 3rd new system irrespective of your IP

EDIT:
The FFXIV Benchmark ran the first Scene smooth afterwards hardly ever a new frame.