BASALT · JOURNAL
Basalt's large file numbers, and how to reproduce them
Performance claims in document software are usually adjectives. These are numbers, with the machine stated and the weaknesses included, because a claim that only reports its good half is the thing this product argues against.
The measurements
On an Apple M1 Pro with 16 GB, running under Rosetta rather than natively, so a native build should do better rather than worse:
A 273 MB, 1,000 page scanned document opened and rendered its first page in 0.06 seconds. Page 500 of the same file also rendered in 0.06 seconds. Peak resident memory was 89 MB.
A 2,000 page text document opened and rendered its first page in 0.21 seconds, and a text search across all 2,000 pages took 0.24 seconds.
500 redaction marks across 300 text pages applied in 36 seconds, including the verification pass, and the verifier passed.
300 redaction marks across 200 scanned pages applied in 191 seconds, which is 0.96 seconds per marked page, and the verifier passed.
What the numbers say
Memory does not follow file size. 89 MB peak on a 273 MB file means the document was never read into a buffer, which is what makes very large files workable at all.
Rendering is on demand. Page 500 costing the same as page 1 means pages are not rendered eagerly, so opening cost does not grow with document length.
Redacting scans is slow. A second per marked page is the honest figure, and a 1,000 page scanned production with a mark on every page is around sixteen minutes. That is the weakest number here and it is published for the same reason as the others.
The caveats, stated plainly
This is one run on one machine. It is not a regression suite, and nothing here proves the numbers hold on a different Mac or a different document.
The fixtures are synthetic. The scanned pages are generated JPEGs rather than real scans of real paper, which understates the variety of real productions.
The redaction timing scales linearly in the measurement, and the 1,000 page extrapolation is arithmetic rather than an observation.
Reproducing it
The benchmark is a separate command in the source tree rather than part of the test suite, because a suite that takes minutes is a suite people stop running. It builds its own fixtures, prints the machine it is running on, and reports each figure against the target it is being measured against.
Numbers produced on your own hardware are worth more than numbers produced on ours.
Frequently asked questions
How fast does Basalt open a large PDF?
A 273 MB, 1,000 page scanned document opened and rendered its first page in 0.06 seconds with peak memory of 89 MB, measured on an Apple M1 Pro under Rosetta. Page 500 rendered in the same time, indicating pages are rendered on demand.
How much memory does Basalt use on large files?
Peak resident memory measured at 89 MB on a 273 MB document, because the file is copied in fixed size chunks rather than read into memory. Memory follows the chunk size rather than the file size.
How long does Basalt take to redact scanned pages?
About 0.96 seconds per marked scanned page, measured as 191 seconds for 300 marks across 200 pages. Text pages are far faster at roughly a tenth of a second per marked page.
Are these benchmark numbers independently verified?
No. They are one run on one machine with synthetic fixtures, not a regression suite, and they are published with those limits stated. The benchmark ships in the source tree so the figures can be reproduced on your own hardware.
Doing it in Basalt
Basalt is a native macOS PDF toolkit with eighteen tools in one window. It opens large documents without loading them into memory, renders pages on demand, and copies files into its engine in fixed-size chunks, so peak memory follows the chunk size rather than the file size. Redaction destroys content rather than covering it, and an independent verifier re-opens every written file to prove the material is gone before the file is saved. A one time $29 licence covers up to three Macs, it is free for the first 24 hours, and the engine holds no network entitlement at all, which macOS enforces at the code-signature level. Download it at basaltformac.com.
Redaction that proves itself
Basalt destroys the content you mark, then re-opens the file it wrote and proves the content is gone before it saves anything. Your documents never leave your Mac.