diff --git a/app/igneum-app/src/ember.rs b/app/igneum-app/src/ember.rs
index fa45e767a..33538c649 100644
--- a/app/igneum-app/src/ember.rs
+++ b/app/igneum-app/src/ember.rs
@@ -1225,6 +1225,11 @@ pub fn amd_knob(shape: Option<&AmdTuneShape>, gclk_now_mhz: f64, linux: bool) ->
     if linux {
         return Err("not available (Linux: the clock and power limits under /sys need root; the tune's helper takes them in a later cut)".into());
     }
+    // PC 1's integrated Radeon (8 October 2026, the exe's read-back): `gmax - gmax_range - - plimit - plimit_range - - factory 0 ok`,
+    // every field a dash (-1 after the parser), an ok line with no tuning interface behind it
+    if t.gmax_max <= t.gmax_min && t.plimit_max <= t.plimit_min {
+        return Err("not available (the driver exposes no tuning interface for this card: the tune line carries no clock or power range)".into());
+    }
     if t.plimit_max < t.plimit_min || t.plimit_min <= -100.0 {
         return Err(format!("not available (the power-limit range {} to {} percent is not usable)", t.plimit_min, t.plimit_max));
     }
@@ -1291,6 +1296,11 @@ mod tests {
         assert!(e.contains("stock clock is not known until the card mines"), "{e}");
         let e = amd_knob(Some(&t9070()), 2970.0, true).unwrap_err();
         assert!(e.starts_with("not available (Linux"), "{e}");
+        // the integrated Radeon's line on PC 1 (8 October 2026): ok, every range a dash; known-failed first (it read as an
+        // offset knob with a one-MHz ladder and a 99 percent power range)
+        let igpu = AmdTuneShape { ok: true, error: String::new(), gmax: -1.0, gmax_min: -1.0, gmax_max: -1.0, plimit_min: -1.0, plimit_max: -1.0 };
+        let e = amd_knob(Some(&igpu), 2100.0, false).unwrap_err();
+        assert!(e.starts_with("not available (the driver exposes no tuning interface"), "{e}");
         assert!(control_reason("amd", &Limits::default(), "amd:gfx1201", true, false).unwrap().contains("not available ("));
     }
 
diff --git a/app/igneum-app/src/engine.rs b/app/igneum-app/src/engine.rs
index 1358ebd16..bb1dbe4f0 100644
--- a/app/igneum-app/src/engine.rs
+++ b/app/igneum-app/src/engine.rs
@@ -5933,6 +5933,20 @@ mod tests {
         assert!(guard < elevated, "the Windows return comes before the unix elevated step");
     }
 
+    /// The two tune lines PC 1 answered on 8 October 2026 (igneum-gpu-telemetry 1d8e055d, the AMD knob's tool): the
+    /// integrated Radeon with no interface reads "not available", the RX 9070 XT reads the offset knob.
+    #[test]
+    fn pc1s_two_tune_lines_give_one_refusal_and_one_knob() {
+        let igpu = super::parse_amd_tune("tune 0 name \"AMD Radeon(TM) Graphics\" gmax - gmax_range - - plimit - plimit_range - - factory 0 ok").unwrap();
+        assert!(igpu.ok && igpu.gmax_max < 0.0 && igpu.plimit_max < 0.0, "{igpu:?}");
+        let shape = |t: &super::AmdTune| crate::ember::AmdTuneShape { ok: t.ok, error: t.error.clone(), gmax: t.gmax, gmax_min: t.gmax_min, gmax_max: t.gmax_max, plimit_min: t.plimit_min, plimit_max: t.plimit_max };
+        assert!(crate::ember::amd_knob(Some(&shape(&igpu)), 2100.0, false).unwrap_err().contains("no tuning interface"));
+        let xt = super::parse_amd_tune("tune 1 name \"AMD Radeon RX 9070 XT\" gmax 0 gmax_range -500 1000 plimit 0 plimit_range -30 10 factory 1 ok").unwrap();
+        let k = crate::ember::amd_knob(Some(&shape(&xt)), 3292.0, false).unwrap();
+        assert_eq!((k.stock_mhz, k.gmax_offset, k.clock_max_mhz, k.clock_min_mhz, k.plimit_min, k.plimit_max), (3292, true, 3292, 2792, -30.0, 10.0), "the live clock under load (3,292 MHz in the read-back sample) is the stock the offsets apply to");
+        assert_eq!(crate::ember::amd_gmax_arg(2992, 3292, true), -300);
+    }
+
     /// PC 2, 7 October 2026, 14:39Z: "the helper did not run sequence 1 within 15 s (no line in ...helper.log)" is a FAULT line
     #[test]
     fn a_helper_that_does_not_answer_is_a_fault_line() {