In a nutshell: Logitech is upgrading the capabilities of its 'Hero' mice with a software update that unlocks tracking at up to 25,600 DPI. You'll have a hard time telling the difference, but the company wants to show gamers that its mice are using a sensor that is more than capable for the job.
If you purchased a Logitech gaming mouse with a 'Hero' optical sensor, you're in for a surprise. The company has issued a firmware update that will greatly increase the maximum sensitivity it can achieve.
The Hero (High Efficiency Rated Optical) sensor typically maxes out at 16,000 DPI, which is why it was dubbed the "Hero 16K" when it was introduced back in 2016. Now that moniker has been changed to "Hero 25K," which gives Logitech bragging rights for having the first mice on the market that come with a sub-micron-level mouse sensor in them.
For reference, the best gaming mice out there top out at 20,000 DPI -- even Logitech admits that at 25,600 DPI the Hero 25K sensor is overkill for what gamers actually need. Still, the company wanted to showcase that it didn't make any compromises with its sensor. This essentially means that your mouse doesn't need any smoothing or corrections for erroneous counts to achieve an accuracy level of 98 percent, all while using ten times less energy when compared to previous Logitech G sensors.
The upgrade is a nice gift to people who purchased a G903 Hero, G502 Lightspeed, Pro Wireless, G703 Hero, G604, G502 Hero, G403 Hero, or a Pro mouse. To install it now, open up the G Hub software and manually check for the update.