Relatively high costs of 8- and 16-channel HD-SDI DVRs used to limit the HD-SDI uptake. However, things are changing due to efforts from increasing chip providers.
A common misunderstanding about storage for HD-SDI solution is that, compared with IP-based systems, due to HD-SDI's lossless compression, HD-SDI requires more storage investment. To clarify, HD video, whether collected via network cameras or HD-SDI cameras, is storage-intensive compared to D1 or lower resolution. After receiving 12bit parallel or sub-LVDS sensor inputs, the ISP provides BT.1120 and composite video outputs directly. Since H.264 is the common compression format, the compressed video processed by network cameras or HD-SDI DVR does not make a big difference. One thing for sure is that HD surveillance systems whether via HD-SDI or network cameras will take more storage space than low-resolution surveillance systems.
HD-SDI video can be stored via HD-SDI DVRs or DVR cards. Stability, recording frame rate are major features to look at when picking storage solutions.