Video becomes laggy when I transfer it to my pc and play it.

When I transfer a video from my iphone to my ixpand drive 32gb, it becomes laggy when I play it on my computer. The format is 1080p at 30fps. Please help me. It would really mean a lot.

Does the video play back normally in the iXpand drive app? If so it may be related to the video codec and the video player on the computer.

what iphone do you have and if it is 7 or above what video format are you capturing in? 7 and above default to “High Efficiency” in settings > camera > formats. this shoots in h.265 which may not work with all media players. if this is the case you can either convert the videos or change the format settings to “Most Compatible” this will shoot in h.264 which is more widely compatible. 

Sometimes it plays normally but when I disconnect the ixpand drive and then reconnect it, somehow the video becomes laggy. The audio even disappears from the video.

I use iPhone 6s.

are the videos shot on the phone or from some other source?

It is from the phone.

I never succeeded transferring videos without any problems with the quality of the video that I recorded with my phone.

i would try connecting the the ixpand to a computer and backing up any data that may be on it. format the ixpand and use exFAT as the file system. after that copy a known good video from the computer to the ixpand and play it from the ixpand and see if there are any issues with the playback. if there not then try copying videos from the phone. If there are still issues the drive may need to be replaced. 

Any tips on how to format the drive? Should i just simply copy all files inside the drive and then format drive then paste back all the files?

Yes that will work. If you are using Windows just format it with default settings and choose exFAT for the file system. if you have a mac you will need to use disk utility and you need to set the partition type to MBR (Master Boot Record) and file system to exFAT. Make sure you set the partition type as Mac defaults to GUID partition and the iXpand Drive app does not work with GUID partition types.