diff --git a/test/amd/test_sqttmap.py b/test/amd/test_sqttmap.py
index eec71b8329..909159ca4c 100644
--- a/test/amd/test_sqttmap.py
+++ b/test/amd/test_sqttmap.py
@@ -78,8 +78,9 @@ class TestSQTTMapBase(unittest.TestCase):
       for event in events:
         if (p:=kern_events.get(event.kern)) is None: continue
         with self.subTest(example=name, kern=event.kern):
+          # skip if there's no SQTT frequency data
           if not (timeline:=sqtt_timeline(event.blob, p.lib, target)): continue
-          frequency = [e.key for e in timeline if type(e).__name__ == "ProfilePointEvent" and e.name == "freq_hz"]
+          if not (frequency:=[e.key for e in timeline if type(e).__name__ == "ProfilePointEvent" and e.name == "freq_hz"]): continue
           mean = sum(frequency) / len(frequency)
           variance = sum((v - mean) ** 2 for v in frequency) / len(frequency)
           self.assertGreater(mean, 0)
@@ -110,5 +111,9 @@ class TestSQTTMapRDNA3(TestSQTTMapBase): target = "gfx1100"
 
 class TestSQTTMapRDNA4(TestSQTTMapBase): target = "gfx1200"
 
+class TestSQTTMapCDNA(TestSQTTMapBase):
+  target = "gfx950"
+  def test_rocprof_inst_traces_match(self): self.skipTest("requires timestamp patching to match rocprof, currently it's off by a few cycles")
+
 if __name__ == "__main__":
   unittest.main()
diff --git a/test/backend/test_asm_gemm.py b/test/backend/test_asm_gemm.py
index f3b2066574..d013ea9804 100644
--- a/test/backend/test_asm_gemm.py
+++ b/test/backend/test_asm_gemm.py
@@ -87,6 +87,9 @@ class TestGemmLarge(unittest.TestCase):
     if not is_cdna4():
       self.skipTest("very slow on non mi350x")
 
+  @Context(ASM_GEMM=1)
+  def test_empty(self): (Tensor.empty(N:=getenv("N", 4096), N, dtype=dtypes.half)@Tensor.empty(N, N, dtype=dtypes.half)).realize()
+
   def test_tiny(self): verify_asm_gemm(1, 256, 256, 64)
   def test_simple(self): verify_asm_gemm(1, N:=getenv("N", 4096), N, N, dtype=dtypes.half)
   def test_gemm(self): verify_asm_gemm(1, 8192, 4096, 14336)
diff --git a/tinygrad/renderer/amd/sqtt.py b/tinygrad/renderer/amd/sqtt.py
index 43a1ce62ac..67d9b1b715 100644
--- a/tinygrad/renderer/amd/sqtt.py
+++ b/tinygrad/renderer/amd/sqtt.py
@@ -139,6 +139,24 @@ class InstOpRDNA4(Enum):
   OTHER_VMEM = 0xbd
   OTHER_VMEM_5 = 0xc1
 
+class InstOpCDNA(Enum):
+  SMEM_RD = 0
+  SALU_32 = 1
+  VMEM_RD = 2
+  VMEM_WR = 3
+  FLAT_WR = 4
+  VALU_32 = 5
+  LDS = 6
+  PC = 7
+  JUMP = 12
+  NEXT = 13
+  FLAT_RD = 14
+  OTHER_MSG = 15
+  SMEM_WR = 16
+  SALU_64 = 17
+  VALU_64 = 18
+  VALU_MAI = 28
+
 # ═══════════════════════════════════════════════════════════════════════════════
 # PACKET TYPE BASE CLASS
 # ═══════════════════════════════════════════════════════════════════════════════
@@ -448,7 +466,7 @@ class CDNA_INST(PacketType):
   encoding = bits[3:0] == 10
   wave = bits[8:5]
   simd = bits[10:9]
-  inst_type = bits[15:11]
+  op = bits[15:11].enum(InstOpCDNA)
 
 class CDNA_INST_PC(PacketType):
   """pkt_fmt=11: 64-bit (MsgInstPc)"""
@@ -612,7 +630,7 @@ def map_insts(data:bytes, lib:bytes, target:str) -> Iterator[tuple[PacketType, I
   def simd_select(p) -> bool: return getattr(p, "cu", 0) == 0 and getattr(p, "simd", 0) == 0
   for p in decode(data):
     if not simd_select(p): continue
-    if isinstance(p, (WAVESTART, WAVESTART_RDNA4)):
+    if isinstance(p, (WAVESTART, WAVESTART_RDNA4, CDNA_WAVESTART)):
       assert p.wave not in wave_pc, "only one inflight wave per unit"
       wave_pc[p.wave] = next(iter(pc_map))
     elif isinstance(p, WAVEEND):
diff --git a/tinygrad/viz/js/index.js b/tinygrad/viz/js/index.js
index 4797e61958..97ef8849dc 100644
--- a/tinygrad/viz/js/index.js
+++ b/tinygrad/viz/js/index.js
@@ -252,7 +252,7 @@ function selectShape(key) {
 const timelineScale = () => d3.scaleLinear().domain([data.first, data.dur]).range([0, document.getElementById("timeline").clientWidth])
 
 function timeAtCycle(clk) {
-  if (clk < data.instSt || clk > data.instEt) return "-";
+  if (clk < data.instSt || clk > data.instEt || data.tracks.get("Shader Clock") == null) return "-";
   let cur = data.instSt, ns = 0, freq = null;
   // walk through all frequency changes and accumulate time in nanoseconds
   for (const [s, v] of data.tracks.get("Shader Clock").valueMap) {
diff --git a/tinygrad/viz/serve.py b/tinygrad/viz/serve.py
index 1b7f9f246f..0020bf4588 100755
--- a/tinygrad/viz/serve.py
+++ b/tinygrad/viz/serve.py
@@ -339,18 +339,20 @@ def load_amd_counters(ctxs:list[dict], profile:list[ProfileEvent]) -> None:
 
 def sqtt_timeline(data:bytes, lib:bytes, target:str) -> list[ProfileEvent]:
   from tinygrad.renderer.amd.sqtt import map_insts, InstructionInfo, PacketType, INST, InstOp, VALUINST, IMMEDIATE, IMMEDIATE_MASK, VMEMEXEC, ALUEXEC
-  from tinygrad.renderer.amd.sqtt import INST_RDNA4, InstOpRDNA4, TS_DELTA_OR_MARK, TS_DELTA_OR_MARK_RDNA4
+  from tinygrad.renderer.amd.sqtt import INST_RDNA4, InstOpRDNA4, TS_DELTA_OR_MARK, TS_DELTA_OR_MARK_RDNA4, CDNA_INST, InstOpCDNA
   ret:list[ProfileEvent] = []
   row_ends:dict[str, Decimal] = {}
   curr_barrier:dict[str, ProfileRangeEvent] = {}
   NS_PER_TICK = 10  # 100MHz
   prev_pair:tuple[int, int]|None = None # (shader, realtime)
+  is_cdna = target.startswith("gfx9")
   def add(name:str, p:PacketType, op:str|None=None, wave:int|None=None, info:InstructionInfo|None=None) -> None:
     row = f"WAVE:{wave}" if (wave:=getattr(p, "wave", wave)) is not None else f"{p.__class__.__name__}:0 {name}"
     # barrier on this row extends to fill the time our wave was waiting
     if (barrier:=curr_barrier.pop(row, None)) is not None: barrier.en = Decimal(p._time)
     ret.append(e:=ProfileRangeEvent(row, TracingKey(op or name, ret=f"PC:{info.pc}" if info else None), Decimal(p._time), Decimal(p._time+1)))
-    if (et:=row_ends.get(row)) is not None and e.st < et: raise RuntimeError(f"packet {p} overlaps another packet in {row}.")
+    # allow CDNA packets to overlap, NOT allowed on RDNA.
+    if (et:=row_ends.get(row)) is not None and e.st < et and not is_cdna: raise RuntimeError(f"packet {p} overlaps another packet in {row}.")
     row_ends[row] = unwrap(e.en)
     if name == "BARRIER": curr_barrier[row] = e
   for p, info in map_insts(data, lib, target):
@@ -363,8 +365,8 @@ def sqtt_timeline(data:bytes, lib:bytes, target:str) -> list[ProfileEvent]:
         freq_hz = (s1 - s0) * 1_000_000_000 // ((r1 - r0) * NS_PER_TICK)
         ret.append(ProfilePointEvent("LINE:Shader Clock", "freq_hz", freq_hz, ts=Decimal(p._time)))
         prev_pair = pair
-    if isinstance(p, (INST, INST_RDNA4)):
-      name = p.op.name if isinstance(p.op, (InstOp, InstOpRDNA4)) else f"0x{p.op:02x}"
+    if isinstance(p, (INST, INST_RDNA4, CDNA_INST)):
+      name = p.op.name if isinstance(p.op, (InstOp, InstOpRDNA4, InstOpCDNA)) else f"0x{p.op:02x}"
       add(name, p, info=info)
     if isinstance(p, (VALUINST, IMMEDIATE)): add(p.__class__.__name__, p, info=info)
     if isinstance(p, IMMEDIATE_MASK): add("IMMEDIATE", p, wave=unwrap(info).wave, info=info)