diff --git a/example/20_grouped_conv_bwd_weight/run_grouped_conv_bwd_weight_example.inc b/example/20_grouped_conv_bwd_weight/run_grouped_conv_bwd_weight_example.inc
index 70c43b81b3..77b120b684 100644
--- a/example/20_grouped_conv_bwd_weight/run_grouped_conv_bwd_weight_example.inc
+++ b/example/20_grouped_conv_bwd_weight/run_grouped_conv_bwd_weight_example.inc
@@ -134,7 +134,7 @@ bool run_grouped_conv_bwd_weight(const ExecutionConfig& config,
         float max_accumulated_value =
             *std::max_element(wei_host_result.mData.begin(), wei_host_result.mData.end());
 
-        const ck::index_t num_accums         = out.GetElementSize() / conv_param.K_;
+        const ck::index_t num_accums = out.GetElementSize() / (conv_param.K_ * conv_param.G_);
         const ck::index_t num_accums_split_k = split_k;
         double rtol = ck::utils::get_relative_threshold<InDataType, WeiDataType, AccDataType>(
             num_accums / num_accums_split_k);
diff --git a/experimental/builder/include/ck_tile/builder/testing/conv/ck_tile.hpp b/experimental/builder/include/ck_tile/builder/testing/conv/ck_tile.hpp
index 133d7d69b7..b0d5b2f8bb 100644
--- a/experimental/builder/include/ck_tile/builder/testing/conv/ck_tile.hpp
+++ b/experimental/builder/include/ck_tile/builder/testing/conv/ck_tile.hpp
@@ -53,11 +53,28 @@ template <auto SIGNATURE, typename InDataType, typename WeiDataType, typename Ou
     if(!Conv::IsSupportedArgument(kargs))
         return RunResult::not_supported("unsupported ck_tile arguments");
 
+    const std::size_t zeroing_size = std::accumulate(std::begin(kargs.wei_g_k_c_xs_lengths.data),
+                                                     std::end(kargs.wei_g_k_c_xs_lengths.data),
+                                                     1,
+                                                     std::multiplies<std::size_t>());
+    auto preprocess                = [&]() {
+        if constexpr(ConvDirectionIsBackwardWeight<SIGNATURE>)
+        {
+            if(args.k_batch > 1)
+            {
+                ck_tile::hip_check_error(
+                    hipMemsetAsync(kargs.wei_ptr, 0, zeroing_size, s_conf.stream_id_));
+            }
+        }
+    };
+
     constexpr index_t minimum_occupancy =
         Conv::GemmPipeline::Scheduler == ck_tile::GemmPipelineScheduler::Intrawave ? 1 : 2;
 
-    return RunResult::from_runtime(ck_tile::launch_kernel(
-        s_conf, ck_tile::make_kernel<minimum_occupancy>(conv, grids, blocks, 0, kargs)));
+    return RunResult::from_runtime(ck_tile::launch_kernel_time_mask(
+        s_conf,
+        preprocess,
+        ck_tile::make_kernel<minimum_occupancy>(conv, grids, blocks, 0, kargs)));
 }
 
 } // namespace detail
diff --git a/profiler/include/profiler/profile_grouped_conv_bwd_weight_impl.hpp b/profiler/include/profiler/profile_grouped_conv_bwd_weight_impl.hpp
index afc88150ed..90cd40f0a1 100644
--- a/profiler/include/profiler/profile_grouped_conv_bwd_weight_impl.hpp
+++ b/profiler/include/profiler/profile_grouped_conv_bwd_weight_impl.hpp
@@ -364,7 +364,8 @@ bool profile_grouped_conv_bwd_weight_impl(int do_verification,
                     using AccDataType =
                         std::conditional_t<std::is_same_v<ComputeType, int8_t>, int32_t, float>;
 
-                    const index_t num_accums         = output.GetElementSize() / conv_param.K_;
+                    const index_t num_accums =
+                        output.GetElementSize() / (conv_param.K_ * conv_param.G_);
                     const index_t num_accums_split_k = split_k_value;
                     // Get maximum accumulated value from reference
                     const std::size_t tensor_size =
@@ -437,7 +438,8 @@ bool profile_grouped_conv_bwd_weight_impl(int do_verification,
                                            ComputeTypeB>;
                     using AccDataType =
                         std::conditional_t<std::is_same_v<ComputeType, int8_t>, int32_t, float>;
-                    const index_t num_accums         = output.GetElementSize() / conv_param.K_;
+                    const index_t num_accums =
+                        output.GetElementSize() / (conv_param.K_ * conv_param.G_);
                     const index_t num_accums_split_k = split_k_value;
                     // Calculate thresholds
                     auto rtol =
diff --git a/test/grouped_convnd_bwd_weight/test_grouped_convnd_bwd_weight_bilinear.cpp b/test/grouped_convnd_bwd_weight/test_grouped_convnd_bwd_weight_bilinear.cpp
index 425114b89b..f1a6cd843f 100644
--- a/test/grouped_convnd_bwd_weight/test_grouped_convnd_bwd_weight_bilinear.cpp
+++ b/test/grouped_convnd_bwd_weight/test_grouped_convnd_bwd_weight_bilinear.cpp
@@ -244,7 +244,8 @@ class TestGroupedConvndBwdWeight : public ::testing::Test
                 float max_accumulated_value =
                     *std::max_element(wei_host.mData.begin(), wei_host.mData.end());
 
-                const ck::index_t num_accums         = out.GetElementSize() / conv_param.K_;
+                const ck::index_t num_accums =
+                    out.GetElementSize() / (conv_param.K_ * conv_param.G_);
                 const ck::index_t num_accums_split_k = split_k;
                 double rtol =
                     ck::utils::get_relative_threshold<InDataType, WeiDataType, AccDataType>(
diff --git a/test/grouped_convnd_bwd_weight/test_grouped_convnd_bwd_weight_scale.cpp b/test/grouped_convnd_bwd_weight/test_grouped_convnd_bwd_weight_scale.cpp
index 19e1bd7b0f..acf6be6c70 100644
--- a/test/grouped_convnd_bwd_weight/test_grouped_convnd_bwd_weight_scale.cpp
+++ b/test/grouped_convnd_bwd_weight/test_grouped_convnd_bwd_weight_scale.cpp
@@ -199,7 +199,8 @@ class TestGroupedConvndBwdWeight : public ::testing::Test
                 float max_accumulated_value =
                     *std::max_element(wei_host.mData.begin(), wei_host.mData.end());
 
-                const ck::index_t num_accums         = out.GetElementSize() / conv_param.K_;
+                const ck::index_t num_accums =
+                    out.GetElementSize() / (conv_param.K_ * conv_param.G_);
                 const ck::index_t num_accums_split_k = split_k;
                 double rtol =
                     ck::utils::get_relative_threshold<InDataType, WeiDataType, AccDataType>(