This article will discuss the results of some experiments I recently ran using a variety of different USB Serial Adapter modules. The point of these experiments was to characterize the performance of USB Serial adapters using genuine USB-UART ICs from well-known manufacturers, such as the FT232RL made by FTDI vs "clones" or "knockoff" ICs often found on various imported USB Serial adopters you can purchase on places like eBay and AliExpress. Toward the end of the article I'll also describe some similar issues that you might experience when using imported Arduino "clones" that also use some of the same ICs found on these imported adapter modules.
Common USB Serial Chipsets
The FTDI FT232RL is perhaps the most common and cloned IC you are likely to find on a USB Serial Adapter module, but there are other legitimate manufacturers that offer similar designs. Here is a list of the ICs that seem to be the most commonly used:
FT232RL - As mentioned above, this IC is very commonly used as the serial adapter on some models of the Arduino.
FT231X - Used as serial bridge on Sparkfun RedBoard Arduino clone
SiLabs CP2102 -
SiLabs CP2104 -
CH430G -