HBM Thermal Asymmetry

Overview

The hbm_thermal_asym virus is unique: it creates a severe physical temperature gradient across the silicon package by hammering a tiny, isolated memory region while simultaneously drawing maximum compute power.

Execution Mechanics

• Extreme Compute Burn: The threads execute a heavy pragma unroll 32 loop of Fused Multiply-Add (FMA) instructions to generate massive die heat.
• Localized Writes: Instead of sweeping across the entire VRAM, it uses a modulo operator to trap all memory writes inside a small, isolated buffer.
• This forces the GPU die to heat up uniformly, but concentrates all memory traffic (and memory heat) onto typically 1 or 2 physical HBM stacks.

Target Subsystems

• Primary Target: HBM Thermal dissipation and physical package gradients.

Failure Symptoms

Critical Failures

• Localized Hotspot Spikes: The active memory stack overheats significantly faster than the rest of the VRAM.
• Memory Controller Crash: The severe temperature difference causes clock stretching or instability on the specific active channel.