i read that you have a setting of 2 x hd 5850 ( are those "spapphire extreme" editions ?), as i have recently bought a l o t of 5830`s and had to
figure it all
(best overclocking, underclocking, over- and undervolting values, really usefully tools, bios editing with rbe (about 70+ VBioses flashed until now, in true hardcore trial and error approach))
out by myself from from the (very) first.
I presume you re using Windows 7/Vista.
That being said, your Problem may be solved easy and efficient via " ATI TRAY TOOLS " , this tool handles 2 GPUs (first is always the one in the primary PCI-E slot)...
Get it here ---- " http://radeon.ru/downloads/att/attsetup.exe
" ---- install ---- restart PC ---- start ati tray tools ----
left click on the icon --- hardware --- overclocking ---- enable box " Apply to both cores/adapters " --- before applying any clocks make sure your voltage setting is appropiate, if not "ATT" lets you add custom vddc.
Hope it helped.
If not use RBE, i may help you with it.