# DifferentialEquations.jl SavingCallback but dont build the whole solution

**URL:** <https://discourse.julialang.org/t/differentialequations-jl-savingcallback-but-dont-build-the-whole-solution/126430>\
**Category:** Modelling & Simulations\
**Tags:** question, diffeq\
**Created:** [February 28, 2025, 5:12pm UTC](https://discourse.julialang.org/t/differentialequations-jl-savingcallback-but-dont-build-the-whole-solution/126430 "2025-02-28T17:12:51Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![svretina](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/svretina/32/206157_2.png) [@svretina](https://discourse.julialang.org/u/svretina)\
**Post date:** [February 28, 2025, 5:12pm UTC](https://discourse.julialang.org/t/differentialequations-jl-savingcallback-but-dont-build-the-whole-solution/126430/1 "2025-02-28T17:12:51Z")

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Hi all,

is it possible to turn off the solution building, meaning to construct the whole object spanning (n\_timesteps, n\_statevector) ? I would like to minimize the strain on the RAM by saving the statevector at each timestep. I can do the latter with a callback. Is there an option to do this or I have to use the init() & step!() functions to manually do this?

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**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [March 1, 2025, 8:39am UTC](https://discourse.julialang.org/t/differentialequations-jl-savingcallback-but-dont-build-the-whole-solution/126430/2 "2025-03-01T08:39:13Z")

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> [@svretina](#):
>
> is it possible to turn off the solution building, meaning to construct the whole object spanning (n\_timesteps, n\_statevector) ? I would like to minimize the strain on the RAM by saving the statevector at each timestep. I can do the latter with a callback. Is there an option to do this or I have to use the init() & step!() functions to manually do this?

`save_on = false`

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<div class="post-metadata">

**Author:** ![svretina](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/svretina/32/206157_2.png) [@svretina](https://discourse.julialang.org/u/svretina)\
**Post date:** [March 3, 2025, 10:39pm UTC](https://discourse.julialang.org/t/differentialequations-jl-savingcallback-but-dont-build-the-whole-solution/126430/3 "2025-03-03T22:39:43Z")

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thank you!