bevel

A calm, efficiency-focused terminal system monitor for Linux. Same territory as btop/htop, different goal: instead of just usage percentages, bevel surfaces the hardware efficiency numbers those tools don't show — CPU clock-vs-load match, package power draw, GPU idle/rc6 residency, memory bandwidth, disk latency/queue depth, and real unprivileged battery power draw — rated in plain language (terrible → amazing) as well as raw numbers.

Metrics that need elevated privileges (RAPL power, perf-based GPU/memory counters) are labeled as unavailable with the exact command to unlock them, never shown as silent zeros.

Install

Debian/Ubuntu (apt repository, recommended): one-time setup, then sudo apt install bevel works like any other package, including future apt upgrades:

curl -fsSL https://nyfeblade.github.io/bevel/bevel-repo.gpg.key | sudo gpg --dearmor -o /usr/share/keyrings/bevel-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/bevel-archive-keyring.gpg] https://nyfeblade.github.io/bevel stable main" | sudo tee /etc/apt/sources.list.d/bevel.list
sudo apt update
sudo apt install bevel

This is a third-party repo (not in Debian/Ubuntu's official archives), signed with a dedicated key published at the URL above — same mechanism most third-party apt sources use (Docker, VS Code, etc).

One-line install (static binary, no dependencies, any distro):

curl -fsSL https://raw.githubusercontent.com/nyfeblade/bevel/main/install.sh | sh

Installs to ~/.local/bin/bevel. Works on any x86_64 Linux distro — the binary is statically linked (musl), so there's nothing to depend on.

Single .deb download:

curl -fsSLO https://github.com/nyfeblade/bevel/releases/latest/download/bevel_amd64.deb
sudo apt install ./bevel_amd64.deb

From source:

git clone https://github.com/nyfeblade/bevel.git
cd bevel
cargo install --path .

Usage

bevel            # live TUI, q/esc to quit
bevel --dump     # headless text dump (scripting/verification)

Unlocking privileged metrics

RAPL power and the perf-based GPU/memory-bandwidth counters need elevated access. Either run under sudo, or grant the capabilities once so you never need root again:

sudo setcap cap_dac_read_search,cap_perfmon+ep $(which bevel)
sudo setcap cap_perfmon+ep $(which perf)

What it shows

• CPU — per-core usage/frequency, hybrid P/E-core detection, package power (RAPL), package/core temperature, fan RPM, and a clock-match efficiency score (is the CPU idling down when idle, or boosting for no reason?).
• GPU — frequency, RAPL PP1 power, rc6 idle residency, render-engine busy time.
• Memory — usage, swap, real read/write bandwidth (perf/uncore_imc).
• Disk — per-device utilization, latency, queue depth, throughput.
• Network — per-interface throughput.
• Battery — real, unprivileged whole-system power draw computed from the fuel gauge (useful when RAPL isn't available).
• Load average, uptime, top processes.

No composite "efficiency score" is invented — a single number spanning CPU/GPU/disk work-per-watt would be arbitrary. Each subsystem gets its own real, labeled number instead.

Build from source

Requires a Rust toolchain (rustup).

cargo build --release
./target/release/bevel

License

MIT