Running a 280x or a 7970 with a 290

[AceCobra1]

Any ideas if this is a good idea?

I know the 7970 runs no problem with similar settings with a 280x in the same rig. I can also run a 7950 and 7970 and 280x mixture but they are not too fond of each other so a bit of a waste of time when configuring intensity, TC and all that... But I want to know, if it is possible to run radeon 290 (not x) with a 280x on the same rig with scrypt mining? I am asking scrypt mining in particular as the 7950 runs at 20 intensity whereas the 280x and 7970 runs at 13 and they don't generally run very well on the same rig although I had a few times where I manage to milk them for what I think is thier max hashes.

I think I can run scrypt jane etc. with these GPU mixtures as they all run at intensity 12 anyway

[amacar]

Use this modified cgminer: http://k-dev.net/cgminer/cgminer-3.7.2-kalroth-20140309.zip

I am now using r9 270 with r9 280x with these settings:
color 0F
cgminer --scrypt -d 0,1 -o stratum+tcp://pool -u user-p pass --thread-concurrency 11200,21568 -I 13,19 --gpu-engine 1055,1150 --gpu-memclock 1500,1500 -w 256 -g 2,1 --no-submit-stale --lookup-gap 2

It this help you, feel free to donate to addresses in my signature