Hi Aspose Team,
We are experiencing significant processing time during PDF-to-TIFF conversion for very large documents and would like to understand whether this behavior is expected and if there are any optimization recommendations.
Environment
- Aspose.Cells for .NET
- Aspose.PDF for .NET
- .NET 6
- Windows Server (AWS EC2 t3.xlarge)
- 4 vCPU
- 16 GB RAM
Workflow
Our production workflow is:
- Convert Native file (Excel) to PDF using Aspose.Cells.
- Apply document stamping to the generated PDF.
- Convert the stamped PDF to TIFF using Aspose.PDF.
The source Excel file was provided by our client and contains:
- 7 worksheets
- Large number of rows and columns on each worksheet
- No custom scaling applied during conversion
After conversion, the generated PDF contains 14,303 pages .
Excel to PDF Conversion Code
private void ConvertExcelToPdf(string inputPath, string outputPdfPath)
{
FontConfigs.DefaultFontName = "Arial";
var workbook = new Workbook(inputPath);
var pdfOptions = new Aspose.Cells.PdfSaveOptions
{
OnePagePerSheet = false,
AllColumnsInOnePagePerSheet = false,
Compliance = PdfCompliance.PdfA1b,
OptimizationType = PdfOptimizationType.MinimumSize,
DisplayDocTitle = true
};
// Worksheet processing omitted for brevity
workbook.Save(outputPdfPath, pdfOptions);
}
PDF to TIFF Conversion Code
private void ConvertToTiff(string inputFilePath, string outputFilePath, bool multiPageTiff)
{
using (var document = new Aspose.Pdf.Document(inputFilePath))
{
int pageCount = document.Pages.Count;
var resolution = new Aspose.Pdf.Devices.Resolution(100);
var tiffSettings = new Aspose.Pdf.Devices.TiffSettings
{
Compression = Aspose.Pdf.Devices.CompressionType.LZW,
SkipBlankPages = false
};
var tiffDevice = new Aspose.Pdf.Devices.TiffDevice(resolution, tiffSettings);
if (multiPageTiff)
{
tiffDevice.Process(document, outputFilePath);
}
}
}
To better understand the performance characteristics, we compared the conversion times of two large Excel-derived PDFs on the same server configuration.
| PDF Pages | Conversion Time |
|---|---|
| 2,908 Pages | ~5 minutes 35 seconds |
| 14,303 Pages | ~16 minutes |
| Sample Client Document | ~16 minutes |
Processing Logs
INFO 2026-06-20 09:16:02,380 - TIFF production - conversion started: 2608.tiff
INFO 2026-06-20 09:16:02,431 - PDF → TIFF conversion started: 2908 pages
INFO 2026-06-20 09:16:02,431 - Creating multi-page TIFF. Pages: 2908
INFO 2026-06-20 09:21:37,670 - Multi-page TIFF created successfully: 2608.tiff
INFO 2026-06-20 09:21:37,670 - TIFF production - conversion finished: 2608.tiff
However, the sample Excel document provided by our client generates a significantly larger PDF and requires approximately 16 minutes to complete the PDF-to-TIFF conversion on the same server.
This suggests that conversion time is influenced not only by page count but also by page complexity, worksheet content, graphics, formulas, formatting, and rendering requirements.
Could you please advise:
- Could you please review whether our current implementation is optimal, or suggest any best practices for improving throughput?
- Are these conversion times expected for documents of this size and complexity?
- Are there any known performance bottlenecks when converting large Excel-generated PDFs to TIFF?
- Is there a recommended configuration or optimization for improving conversion throughput for very large documents (10,000+ pages)?
- Can Aspose provide any guidance on estimating expected conversion time based on page count and document complexity?
We attached the 14k pages file Excel and PDF file
Excel file- 3.87 MB file on MEGA
PDF file- 19.73 MB file on MEGA