There are two distinct processes that the software undertakes during operation:
- Scanning for files
- When scanning, paths of supported files that haven't already been processed are added to a queue.
- Compressing files
- During the compression phase, files are pulled from this queue and compressed.
Our overarching goal when pulling files from the queue is to deliver the biggest compression savings to you as quickly as possible.
To achieve this "big savings up front" model, the processing order is determined by a combination of file type priority and file size.
1. File Type Priority & Rationale
NXPowerLite prioritizes files based on their extension in the following order:
- 1st - JPEG: JPEGs are processed first because they are extremely quick to optimize. Tackling these first delivers immediate storage savings with very little processing time.
- 2nd - PowerPoint: PowerPoint files generally tend to be bloated and contain lots of unoptimized images. Because their content is ripe for compression, processing them early yields massive storage reductions.
- 3rd - Word, PDF, Excel, TIFF, and PNG: These standard document and image formats are processed next in this specific order.
- 4th - Zip: Zip files are intentionally processed last.
We highly recommend disabling Zip file processing for your primary runs. Because we cannot see what is inside a Zip file beforehand, it requires a heavily I/O-intensive process to extract and inspect the contents. Furthermore, Zip archives frequently contain very large files that NXPowerLite cannot compress, which lowers the time-to-savings ratio. Disabling Zip processing certainly speeds things up, and you can always perform a subsequent run with only Zip enabled to pick up those specific savings. Read how to manage file types in NXPowerLite Server.
2. Descending Order of Size
Within each of the file type categories listed above, files are sorted and processed in descending order of size (largest files first). This directly supports the "big savings up front" model by ensuring the heaviest files are reduced as early as possible.
Important: Processing Across Multiple Folders
If you have multiple folders configured for processing, please note that this priority order applies across the entire file set, not on a per-folder basis. The software will look at the global queue and pick the highest priority file, regardless of which of your configured folders it lives in.
Tip for prioritizing specific folders: If you want to guarantee that a specific folder is compressed first, you can temporarily set your other folders to "Inactive" in the NXPowerLite UI. Once your priority folder has been processed, you can switch the others back to active.
Additional Information on Scanning vs. Optimizing
The software doesn't wait for the scanning process to complete before it starts optimizing files.
Because of this, if the scanner happens to find a batch of Word documents before it finds your JPEGs, it will likely start processing those Word documents (in descending size order) as it finds them. Over a large set of files, you will see the overarching priority take effect (JPEGs optimized first, followed by PowerPoints, etc.), but the exact second-by-second order always depends on the order the scanner finds the files and the relative speed of the scanner versus the optimizer.