Large files and slow connections

CBCTHub accepts files up to several GB. But uploading a heavy volume over an unstable connection can be frustrating. Here are tips for the upload to reach the end without cutoffs.

How big is “big”?

• Standard CBCT (small FOV, 200 µm voxel): 200-400 MB. Normal size.
• Large CBCT (full-arch FOV, 100 µm voxel): 600 MB - 1.2 GB.
• High-res CBCT (75 µm voxel or less): 1.5 - 3 GB.
• Studies with multiple takes (dual TMJ): add 2× or 4× the base size.

Tips for slow connections

1. Compress to ZIP first

A 200 MB ZIP uploads faster than 400 loose files of 500 KB each. Per-request HTTP latency adds up significantly with small files.

2. Use cable, not Wi-Fi

If ethernet cable is available at the center, connect your computer with cable while uploading. Wi-Fi has interference and latency spikes; cable is stable.

3. Upload at night

The center's connection is usually better when no one else uses it. If the upload takes long during work hours, leave it running overnight.

4. Automatic resumability

If it cuts off midway, reload the page and drag the same folder again. CBCTHub detects already-uploaded files by hash and only uploads what is missing. No penalty for retries.

5. Don't close the tab during upload

The upload uses browser memory. If you close the tab, you lose the progress. If you need to do something else, open a separate tab and leave the upload one in background.

When you cannot upload from the browser

For extreme files (5+ GB), or very bad connections, consider these alternatives:

• Take the file on USB elsewhere: if your center has very bad connection, upload from a café with good Wi-Fi.
• Pre-process: some scanners let you export with lower resolution without losing diagnostic value (200 µm voxel instead of 75 µm).