diff --git a/Grid/qcd/action/fermion/CayleyFermion5D.h b/Grid/qcd/action/fermion/CayleyFermion5D.h
index e4587308..916bd0c0 100644
--- a/Grid/qcd/action/fermion/CayleyFermion5D.h
+++ b/Grid/qcd/action/fermion/CayleyFermion5D.h
@@ -216,9 +216,13 @@ NAMESPACE_END(Grid);
   template void CayleyFermion5D< A >::MooeeInv    (const FermionField &psi, FermionField &chi); \
   template void CayleyFermion5D< A >::MooeeInvDag (const FermionField &psi, FermionField &chi);
 
+#ifdef GRID_NVCC
+#define  CAYLEY_DPERP_GPU
+#else
 #undef  CAYLEY_DPERP_DENSE
 #define  CAYLEY_DPERP_CACHE
 #undef  CAYLEY_DPERP_LINALG
+#endif
 #define CAYLEY_DPERP_VEC
 
 #endif
diff --git a/Grid/qcd/action/fermion/CayleyFermion5Dgpu.cc b/Grid/qcd/action/fermion/CayleyFermion5Dgpu.cc
new file mode 100644
index 00000000..f99804a5
--- /dev/null
+++ b/Grid/qcd/action/fermion/CayleyFermion5Dgpu.cc
@@ -0,0 +1,247 @@
+/*************************************************************************************
+
+    Grid physics library, www.github.com/paboyle/Grid 
+
+    Source file: ./lib/qcd/action/fermion/CayleyFermion5D.cc
+
+    Copyright (C) 2015
+
+Author: Peter Boyle <pabobyle@ph.ed.ac.uk>
+Author: Peter Boyle <paboyle@ph.ed.ac.uk>
+Author: Peter Boyle <peterboyle@Peters-MacBook-Pro-2.local>
+Author: paboyle <paboyle@ph.ed.ac.uk>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+    See the full license in the file "LICENSE" in the top level distribution directory
+*************************************************************************************/
+/*  END LEGAL */
+
+#include <Grid/qcd/action/fermion/FermionCore.h>
+#include <Grid/qcd/action/fermion/CayleyFermion5D.h>
+
+
+NAMESPACE_BEGIN(Grid);
+
+// Pminus fowards
+// Pplus  backwards..
+template<class Impl>  
+void CayleyFermion5D<Impl>::M5D(const FermionField &psi_i,
+				const FermionField &phi_i, 
+				FermionField &chi_i,
+				Vector<Coeff_t> &lower,
+				Vector<Coeff_t> &diag,
+				Vector<Coeff_t> &upper)
+{
+  chi_i.Checkerboard()=psi_i.Checkerboard();
+  GridBase *grid=psi_i.Grid();
+  auto psi = psi_i.View();
+  auto phi = phi_i.View();
+  auto chi = chi_i.View();
+  int Ls =this->Ls;
+  assert(phi.Checkerboard() == psi.Checkerboard());
+  // 10 = 3 complex mult + 2 complex add
+  // Flops = 10.0*(Nc*Ns) *Ls*vol (/2 for red black counting)
+  M5Dcalls++;
+  M5Dtime-=usecond();
+
+  thread_loop( (int ss=0;ss<grid->oSites();ss+=Ls),{ // adds Ls
+    for(int s=0;s<Ls;s++){
+      auto tmp = psi[0];
+      if ( s==0 ) {
+	spProj5m(tmp,psi[ss+s+1]);
+	chi[ss+s]=diag[s]*phi[ss+s]+upper[s]*tmp;
+
+	spProj5p(tmp,psi[ss+Ls-1]);
+	chi[ss+s]=chi[ss+s]+lower[s]*tmp;
+      } else if ( s==(Ls-1)) {
+	spProj5m(tmp,psi[ss+0]);
+	chi[ss+s]=diag[s]*phi[ss+s]+upper[s]*tmp;
+
+	spProj5p(tmp,psi[ss+s-1]);
+	chi[ss+s]=chi[ss+s]+lower[s]*tmp;
+      } else { 
+	spProj5m(tmp,psi[ss+s+1]);
+	chi[ss+s]=diag[s]*phi[ss+s]+upper[s]*tmp;
+
+	spProj5p(tmp,psi[ss+s-1]);
+	chi[ss+s]=chi[ss+s]+lower[s]*tmp;
+      }
+    }
+  });
+  M5Dtime+=usecond();
+}
+
+template<class Impl>  
+void CayleyFermion5D<Impl>::M5Ddag(const FermionField &psi_i,
+				   const FermionField &phi_i, 
+				   FermionField &chi_i,
+				   Vector<Coeff_t> &lower,
+				   Vector<Coeff_t> &diag,
+				   Vector<Coeff_t> &upper)
+{
+  chi_i.Checkerboard()=psi_i.Checkerboard();
+  GridBase *grid=psi_i.Grid();
+  auto psi = psi_i.View();
+  auto phi = phi_i.View();
+  auto chi = chi_i.View();
+  int Ls =this->Ls;
+  assert(phi.Checkerboard() == psi.Checkerboard());
+
+  // Flops = 6.0*(Nc*Ns) *Ls*vol
+  M5Dcalls++;
+  M5Dtime-=usecond();
+
+  thread_loop( (int ss=0;ss<grid->oSites();ss+=Ls),{ // adds Ls
+    auto tmp = psi[0];
+    for(int s=0;s<Ls;s++){
+      if ( s==0 ) {
+	spProj5p(tmp,psi[ss+s+1]);
+	chi[ss+s]=diag[s]*phi[ss+s]+upper[s]*tmp;
+
+	spProj5m(tmp,psi[ss+Ls-1]);
+	chi[ss+s]=chi[ss+s]+lower[s]*tmp;
+      } else if ( s==(Ls-1)) {
+	spProj5p(tmp,psi[ss+0]);
+	chi[ss+s]=diag[s]*phi[ss+s]+upper[s]*tmp;
+
+	spProj5m(tmp,psi[ss+s-1]);
+	chi[ss+s]=chi[ss+s]+lower[s]*tmp;
+      } else { 
+	spProj5p(tmp,psi[ss+s+1]);
+	chi[ss+s]=diag[s]*phi[ss+s]+upper[s]*tmp;
+
+	spProj5m(tmp,psi[ss+s-1]);
+	chi[ss+s]=chi[ss+s]+lower[s]*tmp;
+      }
+    }
+  });
+  M5Dtime+=usecond();
+}
+
+template<class Impl>
+void CayleyFermion5D<Impl>::MooeeInv    (const FermionField &psi_i, FermionField &chi_i)
+{
+  chi_i.Checkerboard()=psi_i.Checkerboard();
+  GridBase *grid=psi_i.Grid();
+
+  auto psi = psi_i.View();
+  auto chi = chi_i.View();
+
+  int Ls=this->Ls;
+
+  MooeeInvCalls++;
+  MooeeInvTime-=usecond();
+
+  thread_loop((int ss=0;ss<grid->oSites();ss+=Ls),{ // adds Ls
+    auto tmp = psi[0];
+
+    // flops = 12*2*Ls + 12*2*Ls + 3*12*Ls + 12*2*Ls  = 12*Ls * (9) = 108*Ls flops
+    // Apply (L^{\prime})^{-1}
+    chi[ss]=psi[ss]; // chi[0]=psi[0]
+    for(int s=1;s<Ls;s++){
+      spProj5p(tmp,chi[ss+s-1]);  
+      chi[ss+s] = psi[ss+s]-lee[s-1]*tmp;
+    }
+    // L_m^{-1} 
+    for (int s=0;s<Ls-1;s++){ // Chi[ee] = 1 - sum[s<Ls-1] -leem[s]P_- chi
+      spProj5m(tmp,chi[ss+s]);    
+      chi[ss+Ls-1] = chi[ss+Ls-1] - leem[s]*tmp;
+    }
+    // U_m^{-1} D^{-1}
+    for (int s=0;s<Ls-1;s++){
+      // Chi[s] + 1/d chi[s] 
+      spProj5p(tmp,chi[ss+Ls-1]); 
+      chi[ss+s] = (1.0/dee[s])*chi[ss+s]-(ueem[s]/dee[Ls-1])*tmp;
+    }	
+    chi[ss+Ls-1]= (1.0/dee[Ls-1])*chi[ss+Ls-1];
+      
+    // Apply U^{-1}
+    for (int s=Ls-2;s>=0;s--){
+      spProj5m(tmp,chi[ss+s+1]);  
+      chi[ss+s] = chi[ss+s] - uee[s]*tmp;
+    }
+  });
+
+  MooeeInvTime+=usecond();
+
+}
+
+template<class Impl>
+void CayleyFermion5D<Impl>::MooeeInvDag (const FermionField &psi_i, FermionField &chi_i)
+{
+  chi_i.Checkerboard()=psi_i.Checkerboard();
+  GridBase *grid=psi_i.Grid();
+  int Ls=this->Ls;
+
+  auto psi = psi_i.View();
+  auto chi = chi_i.View();
+
+  assert(psi.Checkerboard() == psi.Checkerboard());
+
+  MooeeInvCalls++;
+  MooeeInvTime-=usecond();
+
+  thread_loop((int ss=0;ss<grid->oSites();ss+=Ls),{ // adds Ls
+
+    auto tmp = psi[0];
+
+    // Apply (U^{\prime})^{-dagger}
+    chi[ss]=psi[ss];
+    for (int s=1;s<Ls;s++){
+      spProj5m(tmp,chi[ss+s-1]);
+      chi[ss+s] = psi[ss+s]-conjugate(uee[s-1])*tmp;
+    }
+    // U_m^{-\dagger} 
+    for (int s=0;s<Ls-1;s++){
+      spProj5p(tmp,chi[ss+s]);
+      chi[ss+Ls-1] = chi[ss+Ls-1] - conjugate(ueem[s])*tmp;
+    }
+
+    // L_m^{-\dagger} D^{-dagger}
+    for (int s=0;s<Ls-1;s++){
+      spProj5m(tmp,chi[ss+Ls-1]);
+      chi[ss+s] = conjugate(1.0/dee[s])*chi[ss+s]-conjugate(leem[s]/dee[Ls-1])*tmp;
+    }	
+    chi[ss+Ls-1]= conjugate(1.0/dee[Ls-1])*chi[ss+Ls-1];
+  
+    // Apply L^{-dagger}
+    for (int s=Ls-2;s>=0;s--){
+      spProj5p(tmp,chi[ss+s+1]);
+      chi[ss+s] = chi[ss+s] - conjugate(lee[s])*tmp;
+    }
+  });
+
+  MooeeInvTime+=usecond();
+
+}
+
+#ifdef CAYLEY_DPERP_GPU
+INSTANTIATE_DPERP(WilsonImplF);
+INSTANTIATE_DPERP(WilsonImplD);
+INSTANTIATE_DPERP(GparityWilsonImplF);
+INSTANTIATE_DPERP(GparityWilsonImplD);
+INSTANTIATE_DPERP(ZWilsonImplF);
+INSTANTIATE_DPERP(ZWilsonImplD);
+
+INSTANTIATE_DPERP(WilsonImplFH);
+INSTANTIATE_DPERP(WilsonImplDF);
+INSTANTIATE_DPERP(GparityWilsonImplFH);
+INSTANTIATE_DPERP(GparityWilsonImplDF);
+INSTANTIATE_DPERP(ZWilsonImplFH);
+INSTANTIATE_DPERP(ZWilsonImplDF);
+#endif
+
+NAMESPACE_END(Grid);