# Pytorch DataParallel two gpu Hang

## post by maskjp on Sep 23, 2020

Hi, I have two lambda dual with two TITAN RTX. One pc works fine. But another pc freeze when using Dataparallel.

I got the not working one last mouth.

I tried the solution in this

But got an error message.

And I also try to disable iommu following the following methods. But I found that the iommu is already disabled by default.

Are there any other solutions?

Thanks!

## post by sabalaba on Sep 27, 2020

Hi! Because you’re a Lambda customer, can you please email [support@lambdalabs.com](mailto:support@lambdalabs.com) with your issue? We should be able to fix it quickly.

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