7970 giga,sapphire,powercolor,his,asus..all of them can run with I13..and with edited bios 
)
)How did you edit it? I couldn't figure out how to improve mining speeds on my giga cards.
Using the tpu editor right? WHat values?
I don't have it anymore but it was a rev 1.0 unlocked Gigabyte Windforce OC 7970...and before I had a HIS IceQ X2 7950 without boost.
Tried many bios flashes and it never got better.
Never tried 8191 for tc, always used 8192 or higher xD, and got hw or lower perf when doing more than i 13 (despite the high tc and available system ram ->8gb ddr3)
If you use -g 2 (gpu-threads 2) then anything over intensity of 13 will HW error. If you want to use higher intensities of 18-20 use 1 gpu thread and a high thread concurrency.