Multipath timing constraints not giving expected results

I second rsefton's idea.

The default setup relationship is 2.5ns. When you add a multicycle -setup 2, then the default relatinoship moves to 5ns, which should make timing much easier to meet. But the default hold timing shifts with the setup relationship(long explanation, and maybe look at my TimeQuest User Guide on alterawiki.com for more details), but basically the hold relationship is now a positive 2.5ns. You've shifted the latch window over one cycle, but not made it any bigger. So the router has to add delay to meet the hold timing at the slow corner, and you still fail setup. Really annoying.

When you want to make the latch window bigger, you need to add a multicycle setup of N and multicycle hold of (N-1). So in this case:

set_multicycle_path -from {design_top:u_d|proc:gen_proc[*].u_p|source_reg[*]} -to {design_top:u_d|proc:gen_proc[*].u_p|ram_true_dual:u_ram|altsyncram:*|*:*|*} -setup -end 2

set_multicycle_path -from {design_top:u_d|proc:gen_proc[*].u_p|source_reg[*]} -to {design_top:u_d|proc:gen_proc[*].u_p|ram_true_dual:u_ram|altsyncram:*|*:*|*} -hold -end 1

Now your setup relationship is 5ns and your hold relationship should be 0ns, and it should meet timing.