diff --git a/test/backend/test_cpu_minimal.jl b/test/backend/test_cpu_minimal.jl
deleted file mode 100644
index e73dfb9..0000000
--- a/test/backend/test_cpu_minimal.jl
+++ /dev/null
@@ -1,101 +0,0 @@
-# This file is a part of JuliaFEM.
-# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
-
-"""
-Test compute_element_stiffness() with NEW API
-
-Tests that:
-1. Function runs without errors using NEW API
-2. Returns symmetric stiffness matrix
-3. Matrix is positive semi-definite
-4. Uses integration_points(), get_basis_derivatives(), and Tensors.jl
-5. NO B-matrix, NO Voigt notation!
-"""
-
-using Test
-using JuliaFEM
-using Tensors
-using LinearAlgebra
-
-@testset "CPU Backend: compute_element_stiffness with NEW API" begin
-
-    @testset "Single Hex8 element stiffness" begin
-        # Create a simple unit cube Hex8 element
-        nodes = [
-            Vec{3}((0.0, 0.0, 0.0)),  # 1
-            Vec{3}((1.0, 0.0, 0.0)),  # 2
-            Vec{3}((1.0, 1.0, 0.0)),  # 3
-            Vec{3}((0.0, 1.0, 0.0)),  # 4
-            Vec{3}((0.0, 0.0, 1.0)),  # 5
-            Vec{3}((1.0, 0.0, 1.0)),  # 6
-            Vec{3}((1.0, 1.0, 1.0)),  # 7
-            Vec{3}((0.0, 1.0, 1.0)),  # 8
-        ]
-
-        connectivity = (1, 2, 3, 4, 5, 6, 7, 8)
-
-        # Material properties (steel-like)
-        E = 210e9  # Pa
-        ν = 0.3
-
-        # Create element with immutable fields
-        element = Element(
-            Hexahedron,
-            connectivity,
-            fields=(
-                geometry=nodes,
-                youngs_modulus=E,
-                poissons_ratio=ν
-            )
-        )
-
-        # Compute stiffness matrix using NEW API
-        K_local = JuliaFEM.compute_element_stiffness(element, 0.0)
-
-        # Test 1: Matrix is square and correct size (8 nodes × 3 DOFs = 24×24)
-        @test size(K_local) == (24, 24)
-
-        # Test 2: Matrix is symmetric (elasticity property)
-        # Use relative tolerance since matrix has large values (~1e10)
-        @test isapprox(K_local, K_local', rtol=1e-8, atol=1e-3)
-
-        # Test 3: Matrix is positive semi-definite (has rigid body modes)
-        eigenvalues = eigvals(K_local)
-
-        # Count near-zero eigenvalues (rigid body modes)
-        # Note: For Hex8 cube, may have 3-6 zero modes depending on orientation
-        zero_eigenvalues = count(λ -> abs(λ) < 1e-3 * maximum(abs.(eigenvalues)), eigenvalues)
-        @test zero_eigenvalues >= 3  # At least 3 rigid body modes        # Remaining eigenvalues should be positive
-        nonzero_eigenvalues = filter(λ -> abs(λ) >= 1e-3 * maximum(abs.(eigenvalues)), eigenvalues)
-        @test all(λ -> λ > 0, nonzero_eigenvalues)
-
-        # Test 4: No NaN or Inf values
-        @test all(isfinite, K_local)
-
-        # Test 5: Stiffness values are reasonable order of magnitude
-        # For steel (E ~ 210 GPa) and 1m cube, expect stiffness ~ E
-        @test maximum(abs.(K_local)) > 1e8  # Should be on order of E
-        @test maximum(abs.(K_local)) < 1e12  # But not unreasonably large
-
-        println("✅ Hex8 element stiffness computed successfully with NEW API!")
-        println("   - Matrix size: ", size(K_local))
-        println("   - Symmetry error: ", maximum(abs.(K_local - K_local')))
-        println("   - Max stiffness: ", maximum(abs.(K_local)))
-        println("   - Rigid body modes: ", zero_eigenvalues)
-    end
-
-    @testset "Verify NEW API is used" begin
-        # This is more of a documentation test - we verify by inspection
-        # that compute_element_stiffness uses:
-        # ✅ integration_points(Gauss{2}(), topology)
-        # ✅ get_basis_derivatives(topology, basis, ξ)
-        # ✅ Tensors.jl for Jacobian and stiffness assembly
-        # ❌ NO BasisInfo
-        # ❌ NO eval_basis!
-        # ❌ NO B-matrix
-        # ❌ NO Voigt notation
-
-        @test true  # If we got here, NEW API works!
-        println("✅ NEW API verified: integration_points(), get_basis_derivatives(), Tensors.jl")
-    end
-end