diff --git a/src/northbridge/intel/sandybridge/raminit.c b/src/northbridge/intel/sandybridge/raminit.c
index 9df102afc6..76f62a6a8d 100644
--- a/src/northbridge/intel/sandybridge/raminit.c
+++ b/src/northbridge/intel/sandybridge/raminit.c
@@ -3130,6 +3130,8 @@ static void discover_edges_write_real(ramctr_timing * ctrl, int channel,
 				upper[lane] =
 					min(rn.end - ctrl->edge_offset[i], upper[lane]);
 				edges[lane] = (lower[lane] + upper[lane]) / 2;
+				if (rn.all || (lower[lane] > upper[lane]))
+					die("edge write discovery failed");
 
 			}
 		}