For starters, no need to run the intensity so high. Most people have been doing well at 12. Here's my config for a Sapphire R9 280X:
--scrypt-jane --sj-nfmin 4 --sj-nfmax 30 --sj-time 1388361600 -I 12 --gpu-engine 1150 --gpu-memclock 1250 -w 256 -g 2 --auto-fan --temp-target 70 --temp-overheat 80 --temp-cutoff 85 --shaders 2048
This nets me around 320KHs at a cool 60C. By dropping the intensity, your card will keep cool even at a higher engine clock.
85 page of this topic
look into
GPU_FORCE_64BIT_PTR=1
GPU_MAX_ALLOC_PERCENT=100
GPU_USE_SYNC_OBJECTS=1
No point in adding shaders its not used
I have my r9 290's currently set at
"intensity" : "18" ready for the Nfactor change
( you want to be mining then not passing HW errors
)
I would not push the card past default engine speed until its been settled in
r9 290's tc should be
"thread-concurrency" : "32765", optimal
"thread-concurrency" : "24768",
"thread-concurrency" : "25600",
"thread-concurrency" : "16256", scrypt jane (12800 detected)
PS I used cgminer.conf for my tweaking
also found r9's love smaller worksizes not larger ones
( they like doing heaps of things at the same time single thread)
Current Nfactor R9 290 should be 300 khs
next Nfactor in 100's
but value of coin
increases with each Nfactor change as its harder to mine
