diff --git a/cpp/src/neighbors/detail/nn_descent.cuh b/cpp/src/neighbors/detail/nn_descent.cuh
index 7cec3bae61..941af82a0f 100644
--- a/cpp/src/neighbors/detail/nn_descent.cuh
+++ b/cpp/src/neighbors/detail/nn_descent.cuh
@@ -491,11 +491,12 @@ __device__ __forceinline__ void remove_duplicates(
 template <typename Index_t, typename ID_t = InternalID_t<Index_t>>
 RAFT_KERNEL
 #ifdef __CUDA_ARCH__
-#if (__CUDA_ARCH__) == 750 || ((__CUDA_ARCH__) >= 860 && (__CUDA_ARCH__) <= 890) || \
-  (__CUDA_ARCH__) == 1200
-__launch_bounds__(BLOCK_SIZE)
-#else
+// Use minBlocksPerMultiprocessor = 4 on specific arches
+#if (__CUDA_ARCH__) == 700 || (__CUDA_ARCH__) == 800 || (__CUDA_ARCH__) == 900 || \
+  (__CUDA_ARCH__) == 1000
 __launch_bounds__(BLOCK_SIZE, 4)
+#else
+__launch_bounds__(BLOCK_SIZE)
 #endif
 #endif
   local_join_kernel(const Index_t* graph_new,
diff --git a/cpp/tests/neighbors/ann_cagra.cuh b/cpp/tests/neighbors/ann_cagra.cuh
index 4ddc3bd6a7..c0f80f1e82 100644
--- a/cpp/tests/neighbors/ann_cagra.cuh
+++ b/cpp/tests/neighbors/ann_cagra.cuh
@@ -1035,29 +1035,22 @@ class AnnCagraIndexMergeTest : public ::testing::TestWithParam<AnnCagraInputs> {
         auto database1_view = raft::make_device_matrix_view<const DataT, int64_t>(
           (const DataT*)database.data() + database0_view.size(), database1_size, ps.dim);
 
-        cagra::index<DataT, IdxT> index0(handle_);
-        cagra::index<DataT, IdxT> index1(handle_);
+        cagra::index<DataT, IdxT> index0(handle_, index_params.metric);
+        cagra::index<DataT, IdxT> index1(handle_, index_params.metric);
+        std::optional<raft::host_matrix<DataT, int64_t>> database_host{std::nullopt};
         if (ps.host_dataset) {
+          database_host = raft::make_host_matrix<DataT, int64_t>(handle_, ps.n_rows, ps.dim);
+          raft::copy(database_host->data_handle(), database.data(), database.size(), stream_);
           {
-            std::optional<raft::host_matrix<DataT, int64_t>> database_host{std::nullopt};
-            database_host = raft::make_host_matrix<DataT, int64_t>(database0_size, ps.dim);
-            raft::copy(database_host->data_handle(),
-                       database0_view.data_handle(),
-                       database0_view.size(),
-                       stream_);
             auto database_host_view = raft::make_host_matrix_view<const DataT, int64_t>(
               (const DataT*)database_host->data_handle(), database0_size, ps.dim);
             index0 = cagra::build(handle_, index_params, database_host_view);
           }
           {
-            std::optional<raft::host_matrix<DataT, int64_t>> database_host{std::nullopt};
-            database_host = raft::make_host_matrix<DataT, int64_t>(database1_size, ps.dim);
-            raft::copy(database_host->data_handle(),
-                       database1_view.data_handle(),
-                       database1_view.size(),
-                       stream_);
             auto database_host_view = raft::make_host_matrix_view<const DataT, int64_t>(
-              (const DataT*)database_host->data_handle(), database1_size, ps.dim);
+              (const DataT*)database_host->data_handle() + database0_size * ps.dim,
+              database1_size,
+              ps.dim);
             index1 = cagra::build(handle_, index_params, database_host_view);
           }
         } else {