1. System specs?
2. Is the drive new or long in use?
3. What SSD Toolbox shows about drive health (screenshot welcome)?
Your 535 SSD speed is just same with Spec, if you read 535 Spec carefully, there are 2 different spec: Compressible & Incompressible. Normally both AS-SSD & CDM use Incompressible data to test, that's why the write performance is only around 220MB/s.
In AS SSD, you can click "Compression-Benchmank" under "Tools" menu, to check the performance again
You can find full 535 Spec here: http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-535-spec.pdf