The maximum bandwidth that CX3 can support is limited by the GPIF II block of CX3. As mentioned in TRM it can support till 2.4Gbps. So if you want to use all the 4 lanes, then CX3 can support only 600Mbps/lane. Else the video will not stream properly due to data loss.
On the other hand, if you are only using 2 lanes, then each lane can support up to 1Gbps.
The bandwidth is not limited by the MIPI receiver, but by the GPIF II block inside CX3.
Thanks for the confirmation, Keaj.
Can you please escalate to the documentation team to correct the false claims of 4 Gbps?
For example, here is a erroneous quote from CX3 TRM page 2:
CX3 conforms to the MIPI CSI-2 specification (version 1.01) and supports up to four data lanes with speed
up to 1 gigabits per second (Gbps) per lane for a total bandwidth of 4 Gbps.