The Lexar NQ790 4TB SSD does not come with a built-in heatsink. It operates without a heatsink, but for optimal performance and lower temperatures we recommend the use of an external heatsink, especially in closed systems or with heavy workloads. On well-ventilated desktops it can also work without an additional heatsink.

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.