Test solution of 1d Swift-Hohenberg equation

In[]:=
Clear["Global`*"];​​
The usual form is
∂
t
u[x,t]==u[x,t]-
3
u[x,t]
-2
∂
x,x
u[x,t]-
∂
{x,4}
u[x,t]
​Since there seems to be an issue with derivatives of order >2, I rewrote it as two coupled 2nd-order equations.It still gives a message saying it’s using the max. allowed 10000 grid points and then hangs for a long time.​The actual solution is relatively smooth and, for example when solved by spectral methods, extremely fast to compute in 1d.
In[]:=
Clear["Global`*"];pde=
∂
t
u[x,t]==u[x,t]-
3
u[x,t]
-2v[x,t]-
∂
x,x
v[x,t],v[x,t]==
∂
x,x
u[x,t];l=10;τ=10;bc={u[0,t]==u[l,t],v[0,t]==v[l,t]};​​init=u[x,0]==
4x(l-x)
2
l
,v[x,0]==-
8
2
l
;​​{usol,vsol}=NDSolveValue[{pde,bc,init},{u,v},{x,0,l},{t,0,τ}]
NDSolveValue
:Some of the functions have zero differential order, so the equations will be solved as a system of differential-algebraic equations.
NDSolveValue
:Using maximum number of grid points 10000 allowed by the MaxPoints or MinStepSize options for independent variable x.
Out[]=
$Aborted