My current CPU is even older, i5-8500, and I needed low power so I went with a TPU vs GPU. (just ordered an additional dual TPU).
As Seth mentioned a few posts up, depending on the model size you want to use you may need more than 1 TPU. For me, the Small found almost everything I needed but the Medium was better. It also tagged/labeled more accurately. For example, instead of just classifying a truck it would classify it as a bus (hope that makes sense). A better example would be cat vs a dog. I also tested the Large model but found I didn't need it.
FYI - A couple of my cameras are also monitoring a long distance (I think up to 100-120 feet away) so the objects may be small in the image which makes it even harder. If monitoring closer/larger objects then the Small and maybe even the Tiny model will work for you. I've seen people swear by Frigate and the Tiny model but then their examples are photos of there 20 x 20 deck or people standing right in front of their doorbell camera. If that is the case then Tiny is probably all you need.
I think it was also Seth that also mentioned somewhere that the original models were not targeted towards this audience (BI) and things like books, desks, couch, chair, etc. were being searched for. I remember seeing these when first testing my indoor cameras and was like HUH??? LOL
Hopefully as things progress we'll get better models geared towards this audience (BI), as well as the TPU, and the models will be more efficient.
If only there was a way to just remove the data we don't want from a model.
I know we can build our own models now with the latest version of CPAI but I just haven't had time to look into. Maybe the answer is in there. Maybe the data the model is built from is readily available (like a library) and we just need to copy what we want, leave what we don't want out, and then build the models ourselves. IDK
That being said, thank you to MikeLud, Seth, and all the others (who I know there are more but drawing blanks on the names right now) that are taking the time to build these custom models for us.