Excel Performance Problems

Fix Excel Calculation Slowed Down After Version 2308 Update

Huma Ashraf Ch Sep 30, 2026 868 views

Question details

The user experiences a 70 percent decrease in calculation speed for a large Excel model after updating past version 2307.

How to Fix Excel Calculation Slowdown After Updating to Version 2308

Product: Microsoft Excel
Device & OS: not provided
Scenario: Running large Excel models using ForceFullCalculation, iterative calculations, and Solver workflows.
Observed behavior: Excel calculations become significantly slower after updating to version 2308, specifically impacting iterative workflows and complex models.

Before you start

Before proceeding, verify that your workbook does not contain problematic third-party add-ins or inefficient VBA macros that might independently cause performance issues, and prepare a sanitized version of your file containing no confidential data.

Solution 1Recommended

Report the Build Issue with a Sanitized Workbook

Because this performance drop is tied to a specific Office update, the best course of action is to provide a reproducible file to Microsoft Support via your IT administrator.

When an update introduces a calculation bug (such as the degradation of ForceFullCalculation in version 2308), Microsoft engineers need a reproducible example to patch the software engine.

Create a sanitized copy

Make a duplicate of your slow workbook and replace all confidential data (like names, financials, and emails) with dummy data while keeping the formulas and calculation structures intact.

Upload to cloud storage

Upload the sanitized sample workbook to OneDrive, SharePoint, or another secure cloud service, and generate a shareable link.

Contact Microsoft 365 Admin

Ask your organization's Microsoft 365 administrator to log into the Microsoft 365 admin center.

Open a service request

Have the administrator navigate to the Support section, open a new service request detailing the version 2308 calculation slowdown, and provide the link to your sanitized workbook for investigation.

Report the Build Issue with a Sanitized Workbook

Important Context: Ensure you specify to the support agent that the issue began strictly after an Office update and involves ForceFullCalculation or Solver, so it is not mistakenly dismissed as standard VBA or add-in sluggishness.

Solution 2

Revert to Excel Version 2307 (Temporary Workaround)

If you cannot wait for an official patch, rolling your Office installation back to the previously working build (Version 2307) restores your calculation speeds.

Solution 3

Optimize Calculation and Iterative Settings

Manually controlling when your workbook calculates can help mitigate the immediate impact of the slowdown while working on the file.

Free Microsoft Office alternative

Try WPS Office for Fast, Reliable Spreadsheet Calculations

If Microsoft Excel updates are causing performance regressions in your heavy workbooks, consider switching to WPS Office. It provides a lightweight, highly compatible alternative for handling complex data and iterative calculations without the update-induced lags.

1. Download and Install: Download WPS Office for free from the official website and complete the quick installation process.
2. Open Your Workbook: Launch WPS Spreadsheets and open your existing .xlsx files directly without any conversion.
3. Run Your Calculations: Enjoy fast, uninterrupted calculations for your complex models and workflows.

Lightweight architecture ensures fast loading and smooth calculations for large datasetsFully compatible with Microsoft Excel formats (.xlsx, .xls, .csv)Familiar ribbon user interface requires virtually no learning curveFree to use with powerful built-in data analysis and charting tools

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Frequently Asked Questions

Why did my calculation speed drop after the version 2308 update?

Office updates occasionally introduce changes to the calculation engine, memory management, or background processes. These changes can inadvertently cause performance regressions for specific functions, such as ForceFullCalculation, iterative calculations, or the Solver add-in.

How do I safely sanitize an Excel workbook before sending it to support?

Create a copy of the file and replace sensitive text (like client names or internal IDs) with generic placeholders (e.g., 'Client A'). Replace confidential financial figures with randomized numbers using functions like RANDBETWEEN, ensuring the overall structure, formulas, and performance issues remain intact.

Will disabling hardware graphics acceleration fix my calculation slowdown?

No, hardware graphics acceleration primarily affects UI rendering and chart drawing performance. It does not control the underlying formula calculation speed or the mathematical processing engine in Excel.

Is it safe to stay on an older version of Excel permanently?

It is not recommended to permanently stay on an older version due to missing security patches and bug fixes. Rolling back to a previous version should only be a temporary workaround until Microsoft releases a patch addressing the calculation bug.

Excel & Data Problems