We will need some additional information in order to determine the reason why your SSD is showing 500 MB in stead of the 400 GB it should.
- Make sure you are using the https://downloadcenter.intel.com/download/23929/Intel-Solid-State-Drive-Data-Center-Family-for-PCIe-... Intel® Solid-State Drive Data Center Family for PCIe Drivers.
- Where are you seeing this amount of space? If you are using Windows, you should look for it in Computer Management - Disk Management, then confirm that the drive space is shown and properly partitioned. It is possible that there is unused space in your drive.
- Are you using the SSD as boot drive? or is it a data/secondary drive?
Provide additional system details:
- Operating System version
- SSD model (Add in card or 2.5 in)
- PC brand and model
- Motherboard model
- BIOS version