# \[Nsight Compute\] \[H100\] Questions on L1 Bank Conflict statistic discrepancies between Details and Source pages **URL:** \ **Category:** Nsight Compute\ **Tags:** nsight, kernel\ **Created:** [November 13, 2025, 11:49am UTC](https://forums.developer.nvidia.com/t/nsight-compute-h100-questions-on-l1-bank-conflict-statistic-discrepancies-between-details-and-source-pages/351306 "2025-11-13T11:49:34Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![2609835176](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/2609835176/32/221695_2.png) [@2609835176](https://forums.developer.nvidia.com/u/2609835176)\ **Post date:** [November 13, 2025, 11:49am UTC](https://forums.developer.nvidia.com/t/nsight-compute-h100-questions-on-l1-bank-conflict-statistic-discrepancies-between-details-and-source-pages/351306/1 "2025-11-13T11:49:34Z")
### Post Content Hello everyone, I am currently using **Nsight Compute (version 2025.3.1.0)** on an **H100** GPU to analyze and optimize shared memory bank conflicts within a CUDA kernel. During my analysis, I’ve become confused about the bank conflict statistics presented on two different pages (Details vs. Source), and I’m hoping to get some clarification. #### My Analysis Method: I have been primarily relying on the **`L1 Wavefonts Shared Excessive`** metric in the **Source Page** (SASS view). My understanding is that this metric helps me pinpoint the specific SASS instructions (usually `LDS`) where wavefronts are experiencing significant bank conflicts when accessing shared memory. **Question 1: Is using `L1 Wavefonts Shared Excessive` the correct method to identify the specific instructions causing problematic conflicts?** #### The Discrepancy I Observed: My main confusion arises from this observation: After optimizing my code, I have successfully reduced the **`L1 Wavefonts Shared Excessive`** metric to **zero** for all instructions on the Source Page. However, when I switch back to the **Details Page** and inspect the `Load/Store Instructions` section, I find that the corresponding `LDS` (Load Shared) or `STS` (Store Shared) instructions **still show non-zero values** in the `Bank Conflicts` column (or `Shared Memory Conflicts` column). #### My Specific Questions: This leads me to question the exact definition of the statistics on the `Details` page: **Question 2: What other types of conflicts are included in the `Bank Conflicts` count on the Details Page?** Since the `L1 Wavefonts Shared Excessive` on the Source page is zero, the Details page count must be measuring something in addition to “excessive” conflicts. What else does it include? **Question 3: How should I accurately interpret the metrics under `Memory Analysis` → `L1 Cache` → `Shared Memory Conflicts` in the Details Page?** I notice categories here like `Bank Conflicts` and `Other Conflicts`. - How is the main `Bank Conflicts` value calculated? - Specifically, **what does the `Other Conflicts` category represent?** I’ve seen this `Other` category account for a high percentage in some of my tests. **Question 4: My ultimate goal is to completely eliminate bank conflicts.** If the Source Page (`L1 Wavefonts Shared Excessive`) already shows zero, do I still need to be concerned about the non-zero `Bank Conflicts` count shown for `LDS/STS` instructions on the Details Page? If so, how can I pinpoint their cause? * * * **Summary:** I am trying to understand the precise difference and relationship between the **Details Page** and the **Source Page** when reporting shared memory bank conflicts in Nsight Compute for the H100 architecture. Any insights on how to correctly use these metrics for optimization would be greatly appreciated. Thank you! ---
**Author:** ![veraj](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/veraj/32/256893_2.png) [@veraj](https://forums.developer.nvidia.com/u/veraj)\ **Post date:** [December 2, 2025, 10:27am UTC](https://forums.developer.nvidia.com/t/nsight-compute-h100-questions-on-l1-bank-conflict-statistic-discrepancies-between-details-and-source-pages/351306/2 "2025-12-02T10:27:47Z")
@2609835176 Seems this is same as [[Nsight Compute] [H100] Questions on L1 Bank Conflict statistic discrepancies between Details and Source pages](https://forums.developer.nvidia.com/t/nsight-compute-h100-questions-on-l1-bank-conflict-statistic-discrepancies-between-details-and-source-pages/351780) I will close this one later if no objection. ---
**Author:** ![veraj](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/veraj/32/256893_2.png) [@veraj](https://forums.developer.nvidia.com/u/veraj)\ **Post date:** [December 16, 2025, 10:28am UTC](https://forums.developer.nvidia.com/t/nsight-compute-h100-questions-on-l1-bank-conflict-statistic-discrepancies-between-details-and-source-pages/351306/3 "2025-12-16T10:28:05Z")
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