Failure Modes of Existing Memory Methods
1
MemGPT · flat FIFO queue
pages of every topic share one queue,
so topics mix as the dialogue grows
OS-style paging, but no notion of a topic
in →
one queue · topics interleaved
oldest out, regardless of topic
2
MemoryBank · decay alone
a forgetting curve decides what fades,
but nothing organizes or updates the rest
worst scores of all compared methods
strength only decays · no structure, no update
3
TiM · single-stage hash retrieval
one hash lookup returns similar thoughts,
but cannot preserve cross-topic dependencies
saving thoughts beats raw turns, retrieval is flat
topic A
park
topic B
diet goal
✗
the link between topics is lost
one lookup, one bucket at a time
4
A-Mem · heavy link generation
every note needs multi-step LLM calls to link,
which inflates latency and accumulates errors
13.0 LLM calls per response (Table 3)
LLM call × 13 per response
each step can inject an error
rich graph, slow and fragile to build
(MemoryOS: 4.9 calls)
each method works on a single dimension in isolation · storage structure, retrieval mechanism, or update strategy
no unified system that stores, updates, retrieves and generates together
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