Cost of QCD simulations with n_f=2 dynamical Wilson fermions

TL;DR

This paper estimates the computational cost of full QCD simulations with two flavors of Wilson fermions using hybrid Monte Carlo, providing a cost formula and discussing feasibility on high-performance systems.

Contribution

It introduces a cost estimation method for n_f=2 Wilson fermion simulations based on solver iterations and autocorrelation times, aiding future computational planning.

Findings

Cost formula relates solver iterations to eigenvalues and autocorrelation times.

Timings from SESAM/TxL fix the cost pre-factor.

Light hadron mass calculations are feasible on 100 Tflops systems.

Abstract

Cost estimates for simulations of full QCD with n_f=2 Wilson fermions by hybrid Monte Carlo are presented. The extrapolations are based on the average number of iterations of the iterative solver within the fermionic part of the HMC molecular dynamics, which is closely related to the minimal eigenvalue of M^+M The cost formula is determined as a product of the scaling functions of iterative solver and integrated autocorrelation time as function of the inverse lattice pseudoscalar mass. Timings by SESAM/TxL allow to fix the pre-factor. It is demonstrated that a 2-flavor dynamical determination of light hadron masses with a statistical precision comparable to the corresponding quenched results from CP-PACS can be an appropriate task for a 100 Tflops system.