# Issue with latest version of TDVP

**URL:** <https://itensor.discourse.group/t/issue-with-latest-version-of-tdvp/2063>\
**Category:** ITensor Julia Questions\
**Created:** [October 15, 2024, 1:56pm UTC](https://itensor.discourse.group/t/issue-with-latest-version-of-tdvp/2063 "2024-10-15T13:56:34Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![DavidStrachan1](https://yyz2.discourse-cdn.com/free1/user_avatar/itensor.discourse.group/davidstrachan1/32/165_2.png) [@DavidStrachan1](https://itensor.discourse.group/u/DavidStrachan1)\
**Post date:** [October 15, 2024, 1:56pm UTC](https://itensor.discourse.group/t/issue-with-latest-version-of-tdvp/2063/1 "2024-10-15T13:56:34Z")

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Hi,

The below code seems to run more slowly using version 0.4.10 as opposed to 0.3.0. Any help would be much appreciated.

```auto
using Pkg

Pkg.rm(“ITensorTDVP”)

Pkg.add(PackageSpec(name=“ITensorTDVP”, version=“0.4.10”))

using ITensorTDVP

using ITensors

@show(pkgversion(ITensorTDVP))

@show(pkgversion(ITensors))

N = 50

sites = siteinds(“S=1/2”,N)

os = OpSum()

for j=1:N-2

os += “Sz”,j,“Sz”,j+2

os += 1/2,“S+”,j,“S-”,j+2

os += 1/2,“S-”,j,“S+”,j+2

end

H = MPO(os,sites)

psi0 = randomMPS(sites;linkdims=10)

nsweeps = 5

maxdim = 50

cutoff = [1E-10]

# Compile the code first
ITensorTDVP.tdvp(H,-0.1im,psi0;nsweeps,maxdim,cutoff,outputlevel=0)
if pkgversion(ITensorTDVP) == v"0.4.10"
@time psi = ITensorTDVP.tdvp(H,-0.1im,psi0;nsweeps,maxdim,cutoff,outputlevel=1)
elseif pkgversion(ITensorTDVP) == v"0.3.0"
@time psi = ITensorTDVP.tdvp(H,-0.02im,psi0;nsweeps,maxdim,cutoff,outputlevel=1)
end

```

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<div class="post-metadata">

**Author:** ![kmp5](https://yyz2.discourse-cdn.com/free1/user_avatar/itensor.discourse.group/kmp5/32/251_2.png) [@kmp5](https://itensor.discourse.group/u/kmp5)\
**Post date:** [October 15, 2024, 3:12pm UTC](https://itensor.discourse.group/t/issue-with-latest-version-of-tdvp/2063/2 "2024-10-15T15:12:14Z")

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Hello David,

Can you please report your timing data? Also can you please report on your `versioninfo` and what computer system you are working with?

Thanks,  
Karl

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**Author:** ![mtfishman](https://yyz2.discourse-cdn.com/free1/user_avatar/itensor.discourse.group/mtfishman/32/11_2.png) [@mtfishman](https://itensor.discourse.group/u/mtfishman)\
**Post date:** [October 16, 2024, 1:51am UTC](https://itensor.discourse.group/t/issue-with-latest-version-of-tdvp/2063/3 "2024-10-16T01:51:32Z")

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Closing because this will be discussed in [Newer version of TDVP seems to be much slower](https://itensor.discourse.group/t/newer-version-of-tdvp-seems-to-be-much-slower/2061). @DavidStrachan1 you should be able to edit your previous post to fix the formatting.

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<div class="post-metadata">

**Author:** ![mtfishman](https://yyz2.discourse-cdn.com/free1/user_avatar/itensor.discourse.group/mtfishman/32/11_2.png) [@mtfishman](https://itensor.discourse.group/u/mtfishman)\
**Post date:** [October 16, 2024, 1:51am UTC](https://itensor.discourse.group/t/issue-with-latest-version-of-tdvp/2063/4 "2024-10-16T01:51:41Z")

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<div class="post-metadata">

**Author:** ![mtfishman](https://yyz2.discourse-cdn.com/free1/user_avatar/itensor.discourse.group/mtfishman/32/11_2.png) [@mtfishman](https://itensor.discourse.group/u/mtfishman)\
**Post date:** [October 16, 2024, 2:51am UTC](https://itensor.discourse.group/t/issue-with-latest-version-of-tdvp/2063/5 "2024-10-16T02:51:24Z")

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<div class="post-metadata">

**Author:** ![mtfishman](https://yyz2.discourse-cdn.com/free1/user_avatar/itensor.discourse.group/mtfishman/32/11_2.png) [@mtfishman](https://itensor.discourse.group/u/mtfishman)\
**Post date:** [October 16, 2024, 2:55am UTC](https://itensor.discourse.group/t/issue-with-latest-version-of-tdvp/2063/6 "2024-10-16T02:55:51Z")

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