Lexar's NM790 is a great NVMe PCIe 4.0 gaming SSD, and as we found when we reviewed the 4TB version, it offers great performance at a very reasonable price. While it does not have the latest flash memory and controller chips, the entire setup is very well balanced, and Lexar has done a good job of configuring everything to work well together.

Of course, better gaming SSDs exist, but they are more expensive and the NM790 should be more than fast enough for most gamers. However, the NM790 does not have a very large cache. Let me explain.

NAND flash, a type of memory used in SSDs, is not super fast, especially when writing. So if you are trying to copy a large number of files from your PC's system RAM to the drive, you need to buffer the data somewhere so that the process does not slow down. Also, the table that stores all the locations on the SSD needs to be constantly updated.

So-called DRAM-less SSDs, such as the NM790, use a portion of the host memory or system RAM for table storage, allowing tables to be checked and modified much more quickly than if they were stored in flash memory. Such SSDs can be made even faster by dedicating a portion of the flash memory as a pseudo-version of a faster NAND type, usually known as an SLC cache.

The NM790 has about 280 GB of SLC cache, which allows the drive to copy and write everything at full speed as long as the amount of data needed to write does not exceed this. However, once the cache is full, performance typically drops by about 50%.

This SLC cache is more than large enough for most PC gamers' needs, but if your rig is used for more than just gaming and sustained write performance is important, the Lexar NM800 Pro may be the SSD for you.

This is because the NM800 Pro has 2GB of DDR4 RAM, which, when combined with the SLC portion of the flash memory, roughly doubles the total cache size of the NM790. In other words, the NM800 Pro can run at full speed for much longer than the NM790. Since this DRAM also hosts the location table, it saves a tiny bit of system memory as well.

However, the NM800 Pro's controller chip is not as good as the NM790, so it does not offer the same level of sustained write performance.

If all this talk about DRAM and cache has you a bit perplexed, here's a simpler breakdown: for PC gaming and general use, we recommend the Lexar NM790; for heavy AI use or constant transfer of large files (video If you do a lot of AI or transfer large files constantly (e.g. video editing), we recommend the Lexar NM800 Pro.

At only 7 cents per GB of storage, both are a real bargain and a great SSD upgrade for any gaming PC.