Sequential Read Performance
It's easy to spot that most SATA SSDs deliver very similar sequential performance. The 500GB Vulcan uses the exact same path as the 500GB MX500. You can't even see the Vulcan line other than at QD1 because the two lines overlap through the queue depth range.
Sequential Write Performance
Performance differences start to appear in the sequential write test. Most drives still follow the same path through the queue depths range, but the Vulcan is slightly lower than the majority of the others.
Sustained Sequential Write Performance
The SM2258 controller uses dynamic cache for the SLC buffer. It will run as much of the flash in SLC mode as possible, but the buffer will shrink as you fill the drive with data.