diff --git a/usb_cables.c b/usb_cables.c
index 0cf95fc..b7bc923 100644
--- a/usb_cables.c
+++ b/usb_cables.c
@@ -1376,12 +1376,16 @@ void usb_cables_check_inter(const struct usb_connector_t** connectors, uint8_t c
 	}
 
 	usb_cables_connectors_float(connectors, connectors_nb); // ensure we start in a safe state
+
 	for (uint8_t connector_from = 0; connector_from < connectors_nb; connector_from++) { // test from every connector
 		for (uint8_t pin_from = 0; pin_from < connectors[connector_from]->pins_nb; pin_from++) { // test from every pin
-			for (uint8_t connector_to = 0; connector_to < connectors_nb; connector_to++) { // test to every connector (except itself)
+			for (uint8_t connector_to = connector_from + 1; connector_to < connectors_nb; connector_to++) { // test to every connector (except itself)
 				if (connector_to == connector_from) { // don't test the connector itself since we already did this test
 					continue;
 				}
+				if (connected && connected[connector_to]) { // we already found a connection to this connector
+					continue;
+				}
 				for (uint8_t pin_to = 0; pin_to < connectors[connector_to]->pins_nb; pin_to++) { // test to every pin
 					int8_t connections = usb_cables_check_pins(connectors[connector_from]->pins[pin_from].port, connectors[connector_from]->pins[pin_from].pin, connectors[connector_to]->pins[pin_to].port, connectors[connector_to]->pins[pin_to].pin);
 					if (connections > 0) {