I have to say I'm a firm believer in what I call "Just enough" surveillance. So while there may be applications where very high camera resolutions may be of use in a casino environment, I have yet to discover them.
For instance, take a table game. For poker-based games, Surveillance needs to be able to identify the value and suit of cards and the value and quantity of chips in a stack. That is pretty much it. We also need to be able to view video in either "real time" (typically defined at 15fps to 30fps, depending on the regulating authority). Other table games, like Blackjack, don't depend on card suits but everything else applies.
We found that 1k (720p) is "just enough" to see what we need, as depicted above, and that is what we used. I admit if we were starting over fresh, I would probably go to 2k (1080p), just because that seems to have become the de facto standard and because it would enhance the ability to quantify chip stacks.
There is no need or desire to go to higher resolutions for many reasons:
1. We would not see anything that we need to see any better.
2. It would waste precious storage space.
3. It could stress network, server or workstation capacities.
Regarding the second point, even though storage continues to get cheaper yearly, I believe we are reaching or are already beyond an effective safe limit for RAID-based storage. In our environment, digital evidence is so critical that our systems use RAID 6 with failover controller/transport redundancy. Rebuild time on our existing 3TB HDD-based storage is around 2-1/2 to 3 days. With 8TB drives, I would expect that time to more than double. A week is really way too long to run a system in degraded mode. There's too much chance of encountering another problem during the rebuild process and 8+TB drives are reaching an effective limit on read errors in RAID systems.
For example, many HDD manufacturers claim 1 unrecoverable error per 10^14. 10^14 is 100Tb or 12.5TB (plus or minus) so essentially, you would have about a 1 in 2 chance of encountering an unrecoverable read error each time a disk is overwritten on a 6TB disk. Granted, the loss of one bit from a video frame is rather negligible, but really any loss could become critical under the right (or rather wrong) circumstances. That could include with CRC-based authentication.
NOTICE: This comment was moved from an existing discussion: 4K And 7K Cameras For Casinos?