The main difference between the Lexar NQ790 and the Lexar NM790 lies in several key areas:

## Memory technology
- The Lexar NQ790 uses QLC (Quad-Level Cell) NAND flash memory, which means that each cell stores 4 bits.
- The Lexar NM790, on the other hand, uses TLC (Triple-Level Cell) NAND flash memory, which corresponds to 3 bits per cell.

## Controller and DRAM cache
- Both SSDs use the same Maxiotek MAP1602A controller, but both do without their own DRAM cache and use host memory buffers (HMB) instead.

## Performance
- Read speeds and write speeds may vary slightly, but the NM790 is generally known for its higher sequential read speeds (up to 7400 MB/s) and write speeds (up to 6500 MB/s). The specific speeds of the NQ790 are not detailed in the sources provided, but QLC SSDs tend to have lower write speeds at high levels.

## General performance and usage
- The NM790 is known for its high sequential read speeds and performance in various benchmarks, while the NQ790 is less documented but likely offers similar performance characteristics at a lower price and higher storage capacity per cell.

These differences should be considered when deciding between the two models, depending on the user's specific requirements and priorities.

https://youtu.be/SE-SnaQ77p...

Only the cash is SLC.
Then drops to 90-160 MB/s