Acer Aspire A515-57 Random Shutdown on Linux? Disable Turbo Boost — Here’s How

If your Acer Aspire A515-57 randomly shuts down or reboots under load on Linux, and you’ve already cleaned the fans, replaced the thermal paste, and tried everything you can think of — this post is for you.

I spent months stuck in power-saver mode just to keep my laptop alive. Balanced mode? Instant reboot. Performance mode? Forget about it. I dug through kernel logs, thermal zones, ACPI trip points, earlyoom configs, and swap tuning — none of it was the real fix. The actual solution took one command.

The Symptoms

• Random hard reboots (no graceful shutdown, just dead) under moderate-to-heavy CPU load
• Only stable in power-saver mode via power-profiles-daemon
• Repasting the CPU and cleaning fans did not fix it
• No kernel panic in the logs — the machine just powers off
• The sensors command shows temps well below critical — nothing looks wrong

My Setup

• Laptop: Acer Aspire 5 A515-57
• CPU: 12th Gen Intel i7-1255U
• OS: Ubuntu 24.04 (kernel 6.8.0)
• BIOS: v1.08 (April 2022, no updates available via LVFS)

What I Tried (and Why It Didn’t Work)

1. Checking Thermal Zones

I discovered two chassis sensors — SEN2 and SEN3 — with a critical trip point of just 80°C, set in the BIOS firmware:

SEN2 trip0: critical @ 80°C
SEN3 trip0: critical @ 80°C
TCPU trip0: critical @ 110°C

The CPU can handle 110°C, but the chassis sensors trigger an emergency shutdown at 80°C. These sensors don’t appear in the sensors command — they’re only visible through the sysfs thermal zone interface:

cat /sys/devices/virtual/thermal/thermal_zone2/type  # SEN2
cat /sys/devices/virtual/thermal/thermal_zone3/type  # SEN3

This is partly why the issue is so hard to diagnose. You look at sensors, see 50°C everywhere, and think everything is fine. Meanwhile, a chassis sensor you can’t see is about to pull the plug.

2. Disabling the Thermal Zones

I tried disabling SEN2 and SEN3 entirely:

echo disabled > /sys/class/thermal/thermal_zone2/mode
echo disabled > /sys/class/thermal/thermal_zone3/mode

Switched to balanced mode, ran a stress test — crashed anyway. The Embedded Controller (EC) operates independently of Linux thermal zones. Disabling the zones in Linux doesn’t stop the EC from killing power.

3. Power-Saver Mode

This worked, but at the cost of performance. The CPU was constantly throttled. For months, I lived with it — better slow than dead.

The Actual Fix: Disable Intel Turbo Boost

The root cause is Intel Turbo Boost. The i7-1255U has a base clock of 1.7 GHz but turbo boosts up to 4.7 GHz — nearly 3x. These turbo spikes cause brief but intense voltage and heat surges that trigger the laptop’s Embedded Controller to perform a safety shutdown before the OS or fans can react.

The fix is to disable Turbo Boost:

echo 1 | sudo tee /sys/devices/system/cpu/intel_pstate/no_turbo

That’s it. After applying this, I switched to performance mode, ran stress-ng --cpu $(nproc) --timeout 120s with all cores maxed out, and the CPU stayed at 44°C. No crash. No reboot.

Making It Permanent

To persist across reboots and sleep/wake cycles, create a systemd service:

sudo tee /etc/systemd/system/disable-turbo-boost.service << 'EOF'
[Unit]
Description=Disable Intel Turbo Boost to prevent power-trip reboots
After=multi-user.target
After=suspend.target
After=hibernate.target

[Service]
Type=oneshot
ExecStart=/bin/sh -c 'echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo'
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target
WantedBy=suspend.target
WantedBy=hibernate.target
EOF

sudo systemctl daemon-reload
sudo systemctl enable --now disable-turbo-boost.service

The suspend.target and hibernate.target hooks ensure turbo stays off after waking from sleep, since some BIOSes re-enable it on resume.

Verify It’s Working

# Turbo should be disabled (1 = off)
cat /sys/devices/system/cpu/intel_pstate/no_turbo

# Check your power profile
powerprofilesctl get

# Stress test
stress-ng --cpu $(nproc) --timeout 120s

# Watch temps in another terminal
watch -n 1 sensors

Why This Works

Without turbo, the CPU stays at its base frequency (1.7 GHz across all cores). It generates significantly less heat because power consumption scales worse than linearly with frequency. The chassis cooling — which was always marginal for the turbo power draw — handles the base clock easily.

You lose the turbo burst speed, but you gain the ability to actually use your laptop in balanced or performance mode. For most workloads (browsing, development, video calls), the difference is barely noticeable. What is noticeable is not having your laptop randomly die in the middle of work.

For a deeper understanding, see the kernel documentation on intel_pstate and the Arch Wiki’s guide on CPU frequency scaling.

Summary

• Problem: Acer Aspire A515-57 with i7-1255U reboots randomly under load on Linux
• Root cause: Turbo Boost voltage spikes trigger the Embedded Controller to shut down
• Fix: echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo
• Result: Performance mode, all cores at 100%, 44°C, rock stable

If you’ve been living in power-saver mode just to keep your Acer alive — try this. It might give you your laptop back.

If you’re also running Cloudflare WARP on Linux, you might run into Docker connection resets caused by WARP’s split tunnel policy — another one of those “invisible config” issues that takes hours to track down.