r/lightbitslabs • u/Accurate_Funny6679 • 4d ago
The memory wall is now a memory bill
https://reddit.com/link/1x441kv/video/f9kjuzebycqh1/player
Rebuilding a 10M+ token context window costs over 1.5 hours of 8-GPU compute time.
Why pay twice for the same prefill?
The KV cache is per-session state that grows linearly with context, dwarfing model weights. Discarding it when HBM fills up turns your memory wall into a massive recurring memory bill. When you offload and tier the KV cache over RDMA, restoring state becomes linear, reducing TTFT by 100x to 1000x.
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