AI Grimoire
02 — siblings
objectives/
optimisers/
scaling/memory/distributed/

Training / optimisers

Optimisers

The optimiser decides how a gradient becomes a step. Almost everything at scale is a variant of one adaptive method plus a carefully shaped learning rate, and the shape turns out to matter about as much as the method.

8 entries, 1 of them a stub.

Entries

02.02.1
AdamWstandard
Adaptive moments with weight decay decoupled from the gradient.
O(d)
02.02.2
Gradient Clippingstandard
Bound the update norm so one bad batch cannot destroy a run.
O(P)
02.02.3
Learning-Rate Schedulesstandard
Warmup, cosine decay, and the warmup–stable–decay alternative.
O(1)
02.02.4
Maximal Update Parameterisationcommon
Scale the initialisation and learning rates so the optimum transfers across width.
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02.02.5
Memory-Efficient Optimiserscommon
Adam’s state is twice the model; factorise it, quantise it, or project it.
O(P)
02.02.6
Schedule-Free Optimisationpromising
Averaging in place of a decay schedule, so the run has no fixed horizon.
O(P)
02.02.7
Second-Order Preconditioningstubpromising
Shampoo, Muon and the orthogonalised-update family.
O(d^1.5)
02.02.8
Stochastic Gradient Descentcommon
A step against the gradient, momentum on top, and why it loses to Adam on transformers.
O(P)