Arterial spin labeling (ASL) measures cerebral blood flow (CBF) non-invasively. Compared to the BOLD signal, CBF is quantitative and more directly linked to neural activation, albeit with lower SNR. Due to increased SNR and T1 relaxation time, ultra-high field MRI promises benefits for ASL. However, technical challenges remain to exploit its full potential. Here, we compared 3T and 7T ASL implementations and studied the influence of labeling schemes, resolution, parallel imaging, and field strength on the CBF and BOLD functional contrast. We found 3T pCASL being advantageous for low-resolution and 7T FAIR for high-resolution and acquisitions utilizing parallel imaging.