Excel Benchmarks

Compare-ExcelPerformance.ps1 compares PSWriteOffice against ImportExcel and ExcelFast across common workbook workflows. It writes raw results, a summary, one-line comparison outputs, and metadata under Ignore\Benchmarks\ExcelPerformance\Run-*.

The script uses published OfficeIMO packages by default by setting OfficeIMORoot to .missing-officeimo, so PSWriteOffice measures the package-mode path instead of a local OfficeIMO checkout.

Common Runs

List available scenarios:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -ListScenarios

Fast sanity run:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Smoke

Default comparison run:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Standard

Large comparison run:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Large

Longer comparison run:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Full

Scale stress run:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite SuperLarge

Focus on a specific workflow:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Standard -Scenario objects-default -RowCount 25000 -RepeatCount 5

Run the richer report workbook workflow:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Standard -Scenario report-workbook -RowCount 1000,10000 -RepeatCount 3 -Engine PSWriteOffice,ImportExcel

Run the more operational workbook workflows:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Standard -Scenario objects-title-freeze,multi-sheet-regions,summary-formulas -RowCount 1000,10000,25000 -RepeatCount 3 -Engine PSWriteOffice,ImportExcel

Run the append, update, many-sheet, read-focused, and chart/pivot split workflows:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Standard -Scenario objects-default,append-existing-table,update-existing-workbook,many-small-sheets,named-range-workbook,chart-only-workbook,pivot-only-workbook -RowCount 1000,10000,25000 -RepeatCount 3

Measure export creation without import follow-up timing:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Standard -Scenario objects-default,wide-objects-default -RowCount 25000 -RepeatCount 3 -Engine PSWriteOffice,ImportExcel,ExcelFast -SkipFollowUps

Compare only selected engines:

pwsh -NoLogo -NoProfile -ExecutionPolicy Bypass -File .\Benchmarks\Compare-ExcelPerformance.ps1 -Suite Standard -Engine PSWriteOffice,ExcelFast

Scenario Suites

Smoke is a quick confidence pass for default, table, and report workbook export/import paths.

Standard covers the everyday decisions people make: default export, table export, no-table export, autofit, full-sheet import, range import, no-header reads, used-range DataTable reads, table/named-range metadata reads, append-to-existing-table workflows, update-existing-workbook workflows, wide objects, DataTable input, title/start-row/frozen-header exports, regional multi-sheet workbooks, many-small-sheet workbooks, formula summary sheets, chart-only and pivot-only workbooks, and a full report workbook with a table, freeze row, conditional formatting, validation, a chart, and a pivot table.

Large runs the broad workflow family at 25k, 100k, and 250k rows, including the PSWriteOffice DataSet worksheet path.

Full includes everything in Standard plus a 100k row count, more repeats, and PSWriteOffice-only DataSet worksheet export.

SuperLarge runs scale-safe workflows at 250k, 500k, and 1m rows. It intentionally skips table/autofit/DataSet defaults; use -Scenario and -RowCount when you want to force those expensive paths.

Output Files

Every run writes these files:

• excel-performance-comparison.csv: one row per scenario/row count with fastest engine, per-engine status (tested, failed, not selected, or not supported by scenario), PSWriteOffice rank, PSWriteOffice vs fastest text, competitor timings, file sizes, and compact memory deltas.
• excel-performance-comparison.json: nested comparison data with per-engine rank, timing ratio, file-size ratio, and memory fields.
• excel-performance-summary.csv: median/min/max data grouped by engine and scenario, including median working-set, peak working-set, and managed-memory deltas.
• excel-performance-results.csv: raw per-iteration results, including failures, file size, working-set before/after, peak working set, and managed-memory delta.
• metadata.json: exact module versions including prerelease labels, machine/runtime details, selected suite, engines, filters, module cache paths, and output paths.

For quick reading, start with excel-performance-comparison.csv. See Artifact Schema when you need exact column meanings.

Artifact Schema

excel-performance-results.csv is the raw evidence. Important columns:

• Status / Error: whether the timed operation itself passed.
• WorkbookValidationStatus: post-operation workbook validation result for export scenarios.
• WorkbookOpenStatus: whether PSWriteOffice could open the generated workbook.
• WorkbookOpenXmlStatus: whether Open XML validation passed, failed, or was skipped because validator types were unavailable.
• WorkbookValidationMs: validation time, recorded separately from the timed operation.
• WorkingSetBeforeMB, WorkingSetAfterMB, WorkingSetDeltaMB, PeakWorkingSetDeltaMB, ManagedDeltaMB: memory diagnostics for the operation.

excel-performance-summary.csv groups raw rows by engine, scenario, profile, and row count. It reports median/min/max time, median file size, median memory deltas, and workbook-validation pass/fail/skip counts.

excel-performance-comparison.csv is the comparison view. It includes:

• FastestEngine, FastestMs, and PSWriteOffice rank/ratio text.
• Per-engine status columns: tested, failed, not selected, or not supported by scenario.
• Per-engine workbook validation status and validation time.
• Per-engine median file size and memory deltas.

metadata.json records exact module versions including prerelease labels, machine/runtime details, selected engines/scenarios, module cache paths, OfficeIMO root, and output paths.

Notes

The benchmark records failures as rows in excel-performance-results.csv instead of hiding them. That makes unsupported competitor scenarios visible without stopping the whole run.

Install behavior is controlled by -SkipImportExcelInstall and -SkipExcelFastInstall. Without those switches, missing competitor modules are saved into the benchmark module cache under Ignore.

Workbook validation is enabled by default for export scenarios. Use -SkipWorkbookValidation only when you need raw timing without post-export open/OpenXML checks.