diff --git a/gc_bba_test/source/tests.c b/gc_bba_test/source/tests.c
index ac1ec5e..a3e5b76 100644
--- a/gc_bba_test/source/tests.c
+++ b/gc_bba_test/source/tests.c
@@ -139,6 +139,7 @@ static int t_speed_sweep(char *m, size_t n)
 {
 	u32 saved = bba_speed, s;
 	u32 best = 0;
+	int any = 0;
 	char buf[40];
 	int off = 0;
 	buf[0] = 0;
@@ -149,11 +150,17 @@ static int t_speed_sweep(char *m, size_t n)
 			if (bba_r8(REG_NWAYS) != NWAYS_LINKUP) bad++;
 		off += snprintf(buf + off, sizeof(buf) - off, "%s%u", s ? "," : "",
 		                (unsigned)(bad ? 0 : 1));
-		if (!bad) best = s;
+		if (!bad) { best = s; any = 1; }
 	}
 	bba_speed = saved;
-	snprintf(m, n, "idx0..5 ok=[%s]; highest good = %u", buf, (unsigned)best);
-	return best >= EXI_SPEED32MHZ ? 0 : 1;
+	/* `best` of 0 is ambiguous (index 0 works vs nothing works), so report
+	 * the per-index map and say NONE explicitly. */
+	if (!any)
+		snprintf(m, n, "ok=[%s] NONE work - not an oversampling issue", buf);
+	else
+		snprintf(m, n, "ok=[%s] highest good idx=%u (5=27MHz)", buf,
+		         (unsigned)best);
+	return (any && best >= EXI_SPEED32MHZ) ? 0 : 1;
 }
 
 static int t_gap_sweep(char *m, size_t n)