The performance of your SSD agrees with tests carried out by Gadgets 360.
Kingston A400 SSD Review,
section "Kingston A400 performance" is written:
Sequential read and write speeds came in at 555.9Mbps and 507.2Mbps
respectively when using a queue depth of 32, which saturates the SSD's
controller to get the most efficiency out of it. These scores are
higher than Kingston's published ratings, but are more indicative of
best-case scenario performance. Random read and write speeds came in
at 321.9Mbps and 310.2Mbps respectively.
Without the advantage of the queue depth, sequential read and write
speeds were 502.1Mbps and 490.6Mbps, whereas random speeds were
25.38Mbps and 86.67Mbps respectively. These are still great scores, and performance is way snappier than it would be with a spinning hard
drive. SiSoft SANDRA's physical disk and file system tests gave us
For doing better, you need a higher-grade SSD, preferably NVMe.