The visual vulnerability spectrum: characterizing architectural vulnerability for graphics hardware

With shrinking process technology, the primary cause of transient faults in semiconductors shifts away from high-energy cosmic particle strikes and toward more mundane and pervasive causes---power fluctuations, crosstalk, and other random noise. Smaller transistor features require a lower critical charge to hold and change bits, which leads to faster microprocessors, but which also leads to higher transient fault rates. Current trends, expected to continue, show soft error rates increasing exponentially at a rate of 8% per technology generation. Existing transient fault research in general-purpose architecture, like the well-established architectural vulnerability factor (AVF), assume that all computations are equally important and all errors equally intolerable. However, we observe that the effect of transient faults in graphics processing can range from imperceptible, to bothersome visual artifacts, to critical loss of function. We therefore extend and generalize the AVF by introducing the Visual Vulnerability Spectrum (VVS). We apply the VVS to analyze the effect of increased transient error rate on graphics processors. With this analysis in hand, we suggest several targeted, inexpensive solutions that can mitigate the most egregious of soft error consequences.