Have you tried updating to the latest and last Crimson driver for your GPUs 16.2.1?
How are your displays connected to the GPUs? Have you tried a different cable?
They are connected via HDMI cable and i have tried the latest drivers also.
I will try a different cable. In saying that about half the games work fine so i don't think it is that, but i'll try anyway.
Understood. Unfortunately your GPUs have reached legacy status so there will not be any further driver updates to fix bugs.
Here are some suggestions you can try to resolve the issue:
1. Use a different HDMI cable, go for a high quality cable.
2. Use a different display connection, like displayport.
3. Try different drivers.
4. Update to Windows 10, it's a free upgrade until the 29th of July.
5. Swap your GPUs round in the PCI-E lanes and connect your display to the second GPU instead. J