I wonder if memcached would give me performance benefits and lower my CPU costs.
Memcache blows redis out of the water in terms of raw throughput and latency, like it's not even remotely close on modern lots of cores and big memory machines.
Redis has a more feature rich api, but has fundamentally hobbled itself on a root hash table and concurrency implementation that is circa 1990.
Give memcached a try, even if it means you implement some stuff you currently defer to redis ops. Measure it. Look at the code bases. Make up your own mind about performance and which actually makes your code simpler.
TL;DR: Redis is just doing different things, and the slab allocator is pretty efficient in regards to performance but not memory usage.
It's simple, but I have like 400 updates per second.