Energy, SQLite, streams and micro programs

Every result on this page is from an Apple M4 (macOS 15.5) with Node v26.12.0 and Bun 1.4.4. There are no Linux results for energy, SQLite or streams yet.

Energy (5 Nov 2026)

powermetrics samples CPU package power every 100 ms while the workload runs. The samples are integrated to joules, and the idle baseline (0.18 W) is subtracted. Source: bench/results/2026-11-05-Apple-M4-energy.csv.

workload	unit	xisto	Node	Bun
sieve	joules per run	0.508	1.419	1.176
count lines in a 1 GB log, streaming	joules per run	2.403	6.894	2.384
Todo API list route under load	joules per 100k requests	8.213	11.835	7.962

xisto uses 2.8 times less energy than Node on the sieve and 2.3 times less than Bun. Bun is slightly better on the HTTP list route (3% less) and about even on the stream.

SQLite (5 Nov 2026)

200,000 inserts in one transaction, 2,000 point reads and a scan of 198,000 rows into typed objects, on an in-memory database. xisto uses the node:sqlite API; Bun uses bun:sqlite. Median of 5. Source: bench/results/2026-11-05-Apple-M4-sqlite.csv.

runtime	time	peak RSS	what you ship
Bun	0.07 s	55.7 MB	84.55 MB
xisto	0.09 s	33.8 MB	1.02 MB
Node	0.21 s	151.4 MB	58.38 MB

Bun is faster here. xisto's executable includes SQLite itself.

Streams (5 Nov 2026)

Count the lines containing ERROR in a 977 MB log of 15 million lines, by streaming and by reading the whole file. Median of 3. Source: bench/results/2026-11-05-Apple-M4-streams.csv.

runtime	mode	time	peak RSS
xisto	stream	0.32 s	1.3 MB
xisto	readFileSync	0.32 s	977.8 MB
Bun	stream	0.60 s	56.5 MB
Node	stream	1.14 s	111.8 MB
Node	readFileSync	failed	—

Node's whole-file read fails: a 1 GB string is longer than V8 allows. A stream keeps xisto's memory at the size of one line; reading the whole file costs its size.

Micro programs (7 Nov 2026)

Median of 5, release build unless noted. Source: bench/results/2026-11-07-Apple-M4.csv.

program	xisto	xisto --dev	Node	Bun
fib	0.02 s, 1.3 MB	0.11 s	0.12 s, 66.1 MB	0.03 s, 14.1 MB
mandelbrot	0.52 s, 1.3 MB	2.16 s	0.59 s, 68.9 MB	0.70 s, 16.1 MB
nbody	0.39 s, 1.3 MB	3.78 s	0.49 s, 69.2 MB	0.45 s, 19.2 MB
objects	0.01 s, 1.3 MB	0.06 s	0.08 s, 68.6 MB	0.02 s, 28.4 MB
sieve	0.08 s, 29.9 MB	0.46 s	0.33 s, 296.0 MB	0.23 s, 245.7 MB

--dev compiles at -O0 for a fast edit loop; it is 4 to 10 times slower than release. The experimental QBE backend (--backend=qbe) ran fib in 0.04 s and nbody in 1.16 s, with a 0.04 s compile.

The cross-machine suite (7 Nov 2026)

bench/vm.py runs one suite of small programs on any machine; this is the M4 run, median of 3. Source: bench/results/vm-mac-2026-11-07-final.txt. The ratio is against the better of Node and Bun.

program	what it exercises	xisto	Node	Bun	Xisto vs best
fib	recursion, int	0.022 s	0.120 s	0.040 s	1.83×
sieve	arrays of booleans	0.095 s	0.358 s	0.246 s	2.59×
binarytrees	many short-lived trees (depth 18)	0.243 s	0.440 s	0.389 s	1.60×
closures	10M updates through captured, reassigned variables	0.011 s	0.112 s	0.042 s	3.95×
generators	3M values through nested generators	0.004 s	0.129 s	0.037 s	9.53×
generics	generic functions over 3 types, 2M elements each	0.051 s	0.317 s	0.119 s	2.36×
date	parse, format, local fields of 1M dates	0.146 s	1.043 s	0.456 s	3.13×
regex	validate 400k emails, parse 300k log lines, replace and split 22 MB	0.157 s	0.377 s	0.202 s	1.29×
promise	10k tasks on timers, then small concurrent rounds	0.020 s	0.096 s	0.027 s	1.36×
redos	patterns that make a backtracking engine explode	0.012 s	7.456 s	3.641 s	291.5×

redos tests /^(a+)+$/ against 22 as followed by !, and similar patterns. V8 and JavaScriptCore backtrack, and the time grows exponentially with the input. xisto's default regex engine is linear in the input, so it has nothing to explode. A pattern that needs backtracking (backreferences, lookaround) uses a second engine, which stops with a RangeError after 50 million steps.

Older runs of this suite on Linux and Windows (bench/results/vm-2026-11-07/) predate the work of 9–10 Nov and are not summarized here.

Executable size

	xisto	Node	Bun
fib	69,288 B	61,220,224 B	88,660,864 B
hello HTTP server	111,088 B	61,220,224 B	88,660,864 B
SQLite program	1.02 MB	58.38 MB	84.55 MB

For Node and Bun the size is the runtime binary and its private libraries. Sources: bench/results/2026-11-07-Apple-M4.csv, bench/results/2026-11-07-Apple-M4-http.csv, bench/results/2026-11-05-Apple-M4-sqlite.csv.

See also

• Benchmarks
• The performance model
• Methodology