⚡ Bolt: Lazy load Discrete Fourier Transform (DFT) matrix to save memory#73
⚡ Bolt: Lazy load Discrete Fourier Transform (DFT) matrix to save memory#73makskliczkowski wants to merge 2 commits into
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Initializing a `Lattice` with a large number of sites eagernessly allocated an $N_s \times N_s$ `complex128` zero array for `self._dft`. For $10^6$ sites, this resulted in an attempt to allocate ~14TB of memory causing instant MemoryError/OOM. This commit optimizes this by setting `self._dft = None` on initialization, and safely lazily generating the matrix inside the `dft` property via `self.calculate_dft_matrix()`. Co-authored-by: makskliczkowski <48489493+makskliczkowski@users.noreply.github.com>
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Initializing a `Lattice` with a large number of sites eagernessly allocated an $N_s \times N_s$ `complex128` zero array for `self._dft`. For $10^6$ sites, this resulted in an attempt to allocate ~14TB of memory causing instant MemoryError/OOM. This commit optimizes this by setting `self._dft = None` on initialization, and safely lazily generating the matrix inside the `dft` property via `self.calculate_dft_matrix()`. Co-authored-by: makskliczkowski <48489493+makskliczkowski@users.noreply.github.com>
⚡ Bolt: Lattice Initialization Memory Optimization
💡 What: The
self._dftmatrix (Discrete Fourier Transform matrix) insideLattice.__init__was eagernessly being allocated usingBackend.zeros((self._ns, self._ns), dtype=complex). This was changed toself._dft = Nonewith lazy evaluation added to the@property def dft(self).🎯 Why: For large lattice sites (e.g. 100x100x100 = 1 million sites), the$N_s \times N_s$ matrix equates to a 1,000,000 x 1,000,000 dense complex matrix (~14TB in size). This eagerly requested allocation caused instant memory exhaustion and failed the constructor entirely.
📊 Impact: Initialization times and memory overhead for$10^6$ site simple 3D lattice fell from instant
Latticehave plummeted for large dimensions. A test instantiation of aArrayMemoryErrorto roughly 0.00018 seconds setup time.🔬 Measurement: Try to instantiate a 100x100x100 lattice
SimpleLattice(dim=3, lx=100, ly=100, lz=100)locally. Previous execution crashes immediately, but after the change completes normally.PR created automatically by Jules for task 11273391844401933478 started by @makskliczkowski