diff --git a/examples_cuda/cuda_ispc.h b/examples_cuda/cuda_ispc.h
index 14a50bbb..7b034411 100644
--- a/examples_cuda/cuda_ispc.h
+++ b/examples_cuda/cuda_ispc.h
@@ -68,6 +68,7 @@ static void createContext(
 
   // Create driver context
   checkCudaErrors(cuCtxCreate(&context, 0, device));
+#if 0
   size_t limit;
   checkCudaErrors(cuCtxGetLimit(&limit, CU_LIMIT_STACK_SIZE));
   fprintf(stderr, " stack_limit= %llu KB\n", limit/1024);
@@ -75,6 +76,7 @@ static void createContext(
   fprintf(stderr, " heap_limit= %llu KB\n", limit/1024);
   checkCudaErrors(cuCtxSetLimit(CU_LIMIT_STACK_SIZE,stackLimit));
   checkCudaErrors(cuCtxSetLimit(CU_LIMIT_MALLOC_HEAP_SIZE,heapLimit));
+#endif
 }
 static void destroyContext()
 {
diff --git a/examples_cuda/deferred/Makefile_gpu b/examples_cuda/deferred/Makefile_gpu
index 2d06e3e7..83b45531 100644
--- a/examples_cuda/deferred/Makefile_gpu
+++ b/examples_cuda/deferred/Makefile_gpu
@@ -13,6 +13,8 @@ ISPCFLAGS=-O3 --math-lib=default --target=nvptx64 --opt=fast-math
 LLVM32 = $(HOME)/usr/local/llvm/bin-3.2
 LLVM   = $(HOME)/usr/local/llvm/bin-3.3
 PTXGEN = $(HOME)/ptxgen
+PTXGEN += -opt=3
+PTXGEN += -ftz=1 -prec-div=0 -prec-sqrt=0 -fma=1
 
 LLVM32DIS=$(LLVM32)/bin/llvm-dis
 
diff --git a/examples_cuda/deferred/kernels.cu b/examples_cuda/deferred/kernels.cu
index 85b646c2..2388ea22 100644
--- a/examples_cuda/deferred/kernels.cu
+++ b/examples_cuda/deferred/kernels.cu
@@ -171,7 +171,7 @@ struct Uniform
     shptr[chunk][elem] = value;
   }
 };
-#elif 1
+#elif 0
 template<typename T, int N>
 struct Uniform
 {
@@ -184,7 +184,7 @@ struct Uniform
 
   __device__ inline Uniform()
   {
-#if 0
+#if 1
     if (programIndex == 0)
       data = new T[N];
     ptr[0] = __shfl(ptr[0], 0);
@@ -200,7 +200,7 @@ struct Uniform
   }
   __device__ inline ~Uniform()
   {
-#if 0
+#if 1
     if (programIndex == 0)
       delete data;
 #else
@@ -821,4 +821,5 @@ RenderStatic(InputHeader inputHeaderPtr[],
           inputHeaderPtr, inputDataPtr, visualizeLightCount,
           framebuffer_r, framebuffer_g, framebuffer_b);
     cudaDeviceSynchronize();
+    cudaDeviceSynchronize();
 }
diff --git a/examples_cuda/deferred/kernels1.ispc b/examples_cuda/deferred/kernels1.ispc
index 740d86a3..1c0962cc 100644
--- a/examples_cuda/deferred/kernels1.ispc
+++ b/examples_cuda/deferred/kernels1.ispc
@@ -549,6 +549,7 @@ RenderStatic(uniform InputHeader inputHeaderPtr[],
     launch[num_groups] RenderTile(num_groups_x, num_groups_y,
                                   inputHeaderPtr, inputDataPtr, visualizeLightCount,
                                   framebuffer_r, framebuffer_g, framebuffer_b);
+    sync;
 }
 
 
diff --git a/examples_cuda/mandelbrot_tasks3d/Makefile_gpu b/examples_cuda/mandelbrot_tasks3d/Makefile_gpu
index e5ba555c..e5f8e001 100644
--- a/examples_cuda/mandelbrot_tasks3d/Makefile_gpu
+++ b/examples_cuda/mandelbrot_tasks3d/Makefile_gpu
@@ -13,6 +13,8 @@ ISPCFLAGS=-O3 --math-lib=default --target=nvptx64 --opt=fast-math
 LLVM32 = $(HOME)/usr/local/llvm/bin-3.2
 LLVM   = $(HOME)/usr/local/llvm/bin-3.3
 PTXGEN = $(HOME)/ptxgen
+PTXGEN += -opt=3
+PTXGEN += -ftz=1 -prec-div=0 -prec-sqrt=0 -fma=1
 
 LLVM32DIS=$(LLVM32)/bin/llvm-dis
 
diff --git a/examples_cuda/mandelbrot_tasks3d/mandelbrot_tasks3d.ispc b/examples_cuda/mandelbrot_tasks3d/mandelbrot_tasks3d.ispc
index cd084aec..1f038674 100644
--- a/examples_cuda/mandelbrot_tasks3d/mandelbrot_tasks3d.ispc
+++ b/examples_cuda/mandelbrot_tasks3d/mandelbrot_tasks3d.ispc
@@ -119,5 +119,6 @@ mandelbrot_ispc(uniform float x0, uniform float y0,
 #endif
       mandelbrot_scanline(x0, dx, y0, dy, width, height, xspan, yspan,
                           maxIterations, output);
+    sync;
 }
 #endif
diff --git a/examples_cuda/rt/Makefile_gpu b/examples_cuda/rt/Makefile_gpu
index 82d1d5d2..2eba1da2 100644
--- a/examples_cuda/rt/Makefile_gpu
+++ b/examples_cuda/rt/Makefile_gpu
@@ -13,6 +13,8 @@ ISPCFLAGS=-O3 --math-lib=default --target=nvptx64 --opt=fast-math
 LLVM32 = $(HOME)/usr/local/llvm/bin-3.2
 LLVM   = $(HOME)/usr/local/llvm/bin-3.3
 PTXGEN = $(HOME)/ptxgen
+PTXGEN += -opt=3
+PTXGEN += -ftz=1 -prec-div=0 -prec-sqrt=0 -fma=1
 
 LLVM32DIS=$(LLVM32)/bin/llvm-dis
 
diff --git a/examples_cuda/volume_rendering/Makefile_gpu b/examples_cuda/volume_rendering/Makefile_gpu
index 1a314788..028224ef 100644
--- a/examples_cuda/volume_rendering/Makefile_gpu
+++ b/examples_cuda/volume_rendering/Makefile_gpu
@@ -13,6 +13,8 @@ ISPCFLAGS=-O3 --math-lib=default --target=nvptx64 --opt=fast-math
 LLVM32 = $(HOME)/usr/local/llvm/bin-3.2
 LLVM   = $(HOME)/usr/local/llvm/bin-3.3
 PTXGEN = $(HOME)/ptxgen
+PTXGEN += -opt=3
+PTXGEN += -ftz=1 -prec-div=0 -prec-sqrt=0 -fma=1
 
 LLVM32DIS=$(LLVM32)/bin/llvm-dis
 
diff --git a/examples_cuda/volume_rendering/volume1.ispc b/examples_cuda/volume_rendering/volume1.ispc
index d680bf00..5437b56f 100644
--- a/examples_cuda/volume_rendering/volume1.ispc
+++ b/examples_cuda/volume_rendering/volume1.ispc
@@ -419,4 +419,5 @@ volume_ispc_tasks(uniform float density[], uniform int nVoxels[3],
     uniform int nTasks = ((width+(dx-1))/dx) * ((height+(dy-1))/dy);
     launch[nTasks] volume_task(density, nVoxels, raster2camera, camera2world, 
                                width, height, image);
+    sync;
 }