Specweb Eval

specweb-eval

Towards Energy-Proportional Computing Using Subsystem-Level Power Management — Subramaniam and Feng (2015) (arXiv:1501.02724, 2015)

What this evaluates

Evaluates the energy proportionality and power efficiency of enterprise server subsystems under varying PHP-based e-commerce web workloads. It measures how power consumption scales with session load and identifies non-proportional power draw in uncore components.

Datasets

• SPECweb2009 — total ?; splits: test (-1)

Metrics

• watts (primary) — range: watts
  • Measured directly using a Yokogawa WT210 power meter at the system level. Reported at idle and at 100% load-level (target 13,000 SUS).

Input / output format

Input: System Under Test (Intel Xeon E5-2665, 256 GB RAM, Linux 3.2.0) running Apache PHP Ecommerce workload, with data loaded into RAMFS to minimize disk I/O.

Output: Power consumption readings in watts, throughput in SUS, and response time compliance (95% < 3s, 99% < 5s).

Scoring recipe

power_idle = measure_power()
power_peak = measure_power_at_load(100)
throughput = get_throughput() # SUS
rt_compliance = check_response_times(thresholds=[3s, 5s], percentiles=[0.95, 0.99])
return power_idle, power_peak, throughput, rt_compliance

Common pitfalls

• Uncore subsystem power remains constant regardless of workload load, skewing energy proportionality calculations if only core power is considered.
• Idle power consumption is significant (36–55% of peak), contradicting assumptions of near-zero idle power in traditional servers.
• Disk I/O must be eliminated (using RAMFS) to isolate processor and memory power management effects.

Evidence (verbatim from paper)

In case of SPECweb, the system consumes 54.88% of peak power when idling.

Citation

@misc{subramaniam2015towards,
  title={Towards Energy-Proportional Computing Using Subsystem-Level Power Management},
  author={Subramaniam and Feng (2015)},
  year={2015},
  note={arXiv:1501.02724}
}

• arXiv: 1501.02724