# ITensorGPU Installation - unsure about dependencies and cuTensor **URL:** \ **Category:** ITensor Julia Questions\ **Created:** [April 18, 2024, 11:06am UTC](https://itensor.discourse.group/t/itensorgpu-installation-unsure-about-dependencies-and-cutensor/1643 "2024-04-18T11:06:05Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Pia](https://avatars.discourse-cdn.com/v4/letter/p/6a8cbe/32.png) [@Pia](https://itensor.discourse.group/u/Pia)\ **Post date:** [April 18, 2024, 11:06am UTC](https://itensor.discourse.group/t/itensorgpu-installation-unsure-about-dependencies-and-cutensor/1643/1 "2024-04-18T11:06:05Z")
Dear ITensor Team, I have a question regarding the Installation of ITensorGPU. I really struggle to understand which dependencies are required, i.e. which versions of Julia, Cuda and cuTensor are allowed to run it successfully. Each time I try to install I run into some version-inconsistencies. I’am using the newest version of Julia (1.10.2). I further have a question regarding cuTensor. Is it necessary to download and intsall it from the NVIDIA webpage or is it enough to install the julia cuTensor package? Thank you already and best regards, Pia ---
**Author:** ![Pia](https://avatars.discourse-cdn.com/v4/letter/p/6a8cbe/32.png) [@Pia](https://itensor.discourse.group/u/Pia)\ **Post date:** [April 18, 2024, 12:04pm UTC](https://itensor.discourse.group/t/itensorgpu-installation-unsure-about-dependencies-and-cutensor/1643/2 "2024-04-18T12:04:02Z")
Ah I just stumbled over the fact, that ITensorGPU will soon be deprecated and it might be clever to use already NDTensor instead. I also understood that cuTENSOR is not yet supported, and some operations are still significantly slower than with ITensorGPU. Is there any planned timeline until the packages will be equivalent in speed? Best regards Pia ---
**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:** [April 18, 2024, 12:12pm UTC](https://itensor.discourse.group/t/itensorgpu-installation-unsure-about-dependencies-and-cutensor/1643/3 "2024-04-18T12:12:54Z")
Could you share examples where the new package extension-based GPU code is slower than ITensorGPU? @kmp5 is looking into adding cuTENSOR support to the new package extension, I would be curious if that accounts for the slowdown or if it is something else. ---
**Author:** ![Pia](https://avatars.discourse-cdn.com/v4/letter/p/6a8cbe/32.png) [@Pia](https://itensor.discourse.group/u/Pia)\ **Post date:** [April 18, 2024, 12:18pm UTC](https://itensor.discourse.group/t/itensorgpu-installation-unsure-about-dependencies-and-cutensor/1643/4 "2024-04-18T12:18:41Z")
Hey, thanks for the quick reply. I don’t have any examples myself yet as I still struggle to install ITensorGPU (but I understood now that I have to use an older ITensor and Julia version). The aim of my second post was more to understand, whether these assumptions I got from reading through the posts in this forum are correct, and if it is still worth to put effort into installing ITensorGPU ---
**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:** [April 18, 2024, 12:21pm UTC](https://itensor.discourse.group/t/itensorgpu-installation-unsure-about-dependencies-and-cutensor/1643/5 "2024-04-18T12:21:56Z")
We would hope that you would not have to install ITensorGPU. The only missing feature in the new package extension compared to ITensorGPU that I know of currently is lack of `cuTENSOR` support, which we are in the process of adding now, but we have seen good speeds without that (though we haven’t done careful comparisons yet). So please try out the new package extension and let us know if you have any issues. ---
**Author:** ![Pia](https://avatars.discourse-cdn.com/v4/letter/p/6a8cbe/32.png) [@Pia](https://itensor.discourse.group/u/Pia)\ **Post date:** [April 18, 2024, 12:47pm UTC](https://itensor.discourse.group/t/itensorgpu-installation-unsure-about-dependencies-and-cutensor/1643/6 "2024-04-18T12:47:19Z")
Alright then, I will try and let you know! ---
**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:** [April 18, 2024, 3:51pm UTC](https://itensor.discourse.group/t/itensorgpu-installation-unsure-about-dependencies-and-cutensor/1643/7 "2024-04-18T15:51:57Z")
**EDIT:** In case it is needed (say for comparing performance or using `cuTENSOR` for the time being), you should be able to install `ITensorGPU` with `using Pkg; Pkg.add("ITensorGPU")`. However, note that you can only use `ITensorGPU` with Julia 1.6 through 1.9, Julia 1.10 and beyond are not and will not be supported.