May be try with this one  samsung 3.2. its not that tight.
TRCDW=14 TRCDWA=14 TRCDR=25 TRCDRA=25, CL 21

777000000000000022CC1C00CEE55C46C0590E1532CD66090060070014051420FA8900A00300000 012123442C3353C19

or

copy your original bios 1500 strap to 2000. This would work too.

p.s. I see no real need to undervolt the mem to 900 since your core volt is not that low. you can keep the mem at 1000.