  The Gemini Planet Imager is a high-contrast near-infrared instrument
specifically designed to image exoplanets and circumstellar disks over a narrow
field of view. We use science data and AO telemetry taken during the first 1.5
yr of the GPI Exoplanet Survey to quantify the performance of the AO system. In
a typical 60 sec H-band exposure, GPI achieves a 5$\sigma$ raw contrast of
10$^{-4}$ at 0.4"; typical final 5$\sigma$ contrasts for full 1 hr sequences
are more than 10 times better than raw contrasts. We find that contrast is
limited by bandwidth wavefront error over much of the PSF. Preliminary
exploratory factor analysis can explain 60-70% of the variance in raw contrasts
with combinations of seeing and wavefront error metrics. We also examine the
effect of higher loop gains on contrast by comparing wavefront error maps
reconstructed from AO telemetry to concurrent IFS images. These results point
to several ways that GPI performance could be improved in software or hardware.
