diff --git a/devito/arch/archinfo.py b/devito/arch/archinfo.py
index 1a17ba6da1..3166bf255a 100644
--- a/devito/arch/archinfo.py
+++ b/devito/arch/archinfo.py
@@ -1008,6 +1008,12 @@ class Device(Platform):
     "warp" in NVidia GPUs and a "wavefront" in AMD GPUs.
     """
 
+    thread_group_slots = None
+    """
+    Number of thread groups issue/execution slots per compute engine (e.g.
+    SM for Nvidia GPUs, CU for AMD GPUs).
+    """
+
     def __init__(self, name, cores_logical=None, cores_physical=None, isa='cpp',
                  max_threads_per_block=1024, max_threads_dimx=1024,
                  max_threads_dimy=1024, max_threads_dimz=64,
@@ -1091,6 +1097,7 @@ def march(self):
 class NvidiaDevice(Device):
 
     thread_group_size = 32
+    thread_group_slots = 4
 
     max_mem_trans_nbytes = 128
 
@@ -1182,6 +1189,7 @@ class Blackwell(Hopper):
 class AmdDevice(Device):
 
     thread_group_size = 64
+    thread_group_slots = 4
 
     max_mem_trans_nbytes = 256
 
diff --git a/devito/types/array.py b/devito/types/array.py
index bd7747d40d..13d3b105a2 100644
--- a/devito/types/array.py
+++ b/devito/types/array.py
@@ -653,7 +653,13 @@ def indices(self):
 
     @property
     def dtype(self):
-        return self.function.dtype
+        try:
+            return self.function.c0.dtype
+        except AttributeError:
+            # Vector-component access over a scalar symbol, e.g. a float4 register.
+            if self.function.is_Symbol:
+                return dtypes_vector_mapper.get_base_dtype(self.function.dtype)
+            raise
 
     @cacheit
     def sort_key(self, order=None):
diff --git a/tests/test_symbolics.py b/tests/test_symbolics.py
index 49f134148f..48709d7cd1 100644
--- a/tests/test_symbolics.py
+++ b/tests/test_symbolics.py
@@ -20,7 +20,7 @@
     SizeOf, VectorAccess, evalrel, pow_to_mul, retrieve_derivatives, retrieve_functions,
     retrieve_indexed, uxreplace
 )
-from devito.tools import CustomDtype, as_tuple
+from devito.tools import CustomDtype, as_tuple, dtypes_vector_mapper
 from devito.types import (
     Array, Bundle, ComponentAccess, FIndexed, LocalObject, Object, StencilDimension
 )
@@ -575,6 +575,13 @@ def test_component_access():
     assert cf2 == cf1
 
 
+def test_component_access_symbol_printing():
+    acc = dSymbol(name='acc', dtype=dtypes_vector_mapper[(np.float32, 4)])
+    expr = ComponentAccess(acc, 0)
+
+    assert ccode(sympy.Float('1.25')*expr, dtype=expr.dtype) == '1.250F*acc.x'
+
+
 def test_vector_access():
     grid = Grid(shape=(3, 3, 3))