Cycles: Make CUDA 7.5 officially recommended

This was a hard decision, because going newer CUDA toolkit makes
rendering up to 5% slower. But on another hand, it solves major
speed regressions (up to 30%) with branched path tracing on a
top level cards.

Neither of those regressions have a meaningful and sane workaround
from the code itself.

Toolkit 6.5 could still be used, but it's no longer recommended one.

1 files changed, 3 insertions, 3 deletions

diff --git a/intern/cycles/device/device_cuda.cpp b/intern/cycles/device/device_cuda.cpp
index 98997ae0968..80c8cb1e592 100644
--- a/intern/cycles/device/device_cuda.cpp
+++ b/intern/cycles/device/device_cuda.cpp
@@ -310,11 +310,11 @@ public:
 			return "";
 		}
 		if(cuda_version < 60) {
-			printf("Unsupported CUDA version %d.%d detected, you need CUDA 6.5.\n", cuda_version/10, cuda_version%10);
+			printf("Unsupported CUDA version %d.%d detected, you need CUDA 7.5.\n", cuda_version/10, cuda_version%10);
 			return "";
 		}
-		else if(cuda_version != 65)
-			printf("CUDA version %d.%d detected, build may succeed but only CUDA 6.5 is officially supported.\n", cuda_version/10, cuda_version%10);
+		else if(cuda_version != 75)
+			printf("CUDA version %d.%d detected, build may succeed but only CUDA 7.5 is officially supported.\n", cuda_version/10, cuda_version%10);
 
 		/* compile */
 		string kernel = path_join(kernel_path, path_join("kernels", path_join("cuda", "kernel.cu")));