s3: reduce a bit the intensity on windows

x11/s3.cu

@@ -57,7 +57,12 @@ extern "C" int scanhash_s3(int thr_id, uint32_t *pdata,
 	unsigned long *hashes_done)
 {
 	const uint32_t first_nonce = pdata[19];
+#ifdef WIN32
+	// reduce a bit the intensity on windows
+	const int throughput = 256 * 256 * 8;
+#else
 	const int throughput = 256 * 256 * 8 * 2;
+#endif
 
 	static bool init[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };