Lightroom Adjustment Brush Unusable / Slow & Erratic

i updated lightroom cc version , when using adjustment brush (with , without overlay) lightroom becomes incredibly slow or unresponsive. not produces brushstrokes never did i.e. use brush on 1 area , stop wait , see before strokes made fill in, seem 10-20 seconds on average, unacceptable, , lightroom proceeds make big random stroke on areas never hovered on let alone brushed in. then, go on erase random erroneous stroke, problem repeats in removes not error, portion of filled in. used 5 minute edit, tops, hour long ordeal mediocre results @ best. far tried updating drivers, changing cache size, giving lightroom process higher priority many restarts think power button fall off. computer has 32 gb ram, 5930k i7, evga gtx 980ti, m.2 , reg. sataiii ssds. running windows 10 pro. many years of running older versions of lightroom on 2009 mac pro , mid 2014 macbook pro more confident have enough resources in machine smack lightroom dead many times over, , sure enough when check task manager can see lightroom barely scratches 10% on cpu , @ best went 4.4 gb of ram @ time unresponsive. far can tell computer doesn't register heavy loads in of components of stays nice , quiet. 

 

any on issue appreciated: how lightroom use more 10% of resources? how can adjustments brush work? there way downgrade let's lr4 or lr5? improve mess can finish work.

 

thanks.

 

chris

 

p.s. photoshop, illustrator, indesign, brackets, hasselblad phocus (just test) work fine without freezing or input problems.

hi christopherw,

 

please turn off graphics processor lightroom preferences.

 

open lightroom

go lightroom preferences edit menu

click on performance tab

uncheck graphics processor

restart lightroom

 

let know if helps.

regards,

mohit

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