Features like sub-pixel precision and the GTE Accuracy hack reduce the "polygon jitter" common in original PS1 hardware.
Unlike older software plugins that struggled with high resolutions, the GPU Core 2.0.0 leverages and GLSL shaders to drastically improve graphics while maintaining performance.
When prompted for Video configuration, select ePSXe GPU Core 2.0.0 from the dropdown menu. Best Configuration for High Graphics