In the 1-to-many mode a user presents biometric data such as a fingerprint or retina scan and the reader then compares the live scan to all the templates stored in the memory. This method is preferred by most end-users, because it eliminates the need to carry ID cards or use PINs. On the other hand, this method is slower, because the reader may have to perform thousands of comparison operations until it finds the match. An important technical characteristic of a 1-to-many reader is the number of comparisons that can be performed in one second, which is considered the maximum time that users can wait at a door without noticing a delay. Currently most 1-to-many readers are capable of performing 2,000–3,000 matching operations per second. 

The advantage of using barcode technology is that it is cheap and easy to generate the credential and it can easily be applied to cards or other items. However the same affordability and simplicity makes the technology susceptible to fraud, because fake barcodes can also be created cheaply and easily, for example by photocopying real ones. One attempt to reduce fraud is to print the barcode using carbon-based ink, and then cover the bar code with a dark red overlay. The barcode can then be read with an optical reader tuned to the infrared spectrum, but can not easily be copied by a copy machine. This does not address the ease with which barcode numbers can be generated from a computer using almost any printer.
An important feature for memory card readers is the speed with which they can transmit data. Readers with USB 3.0 compatibility will be faster than USB 2.0 technology (as long as your computer has a USB 3.0 port). As mentioned earlier, there are various types of memory cards, so having a reader than can communicate with more than one interface will be beneficial, especially if you find yourself using multiple memory cards.
All biometric readers work similarly, by comparing the template stored in memory to the scan obtained during the process of identification. If there is a high enough degree of probability that the template in the memory is compatible with the live scan (the scan belongs to the authorized person), the ID number of that person is sent to a control panel. The control panel then checks the permission level of the user and determines whether access should be allowed. The communication between the reader and the control panel is usually transmitted using the industry standard Wiegand interface. The only exception is the intelligent biometric reader, which does not require any panels and directly controls all door hardware.
The outdated, missing or incompatible device driver can also cause other Windows problems, like black screen after Windows update, USB device not recognized issue, hardware device error code 43, etc. In this case, you can use Driver Talent, the safest and fastest way to update drivers to help to download and install the compatible card reader driver or USB driver for Windows 10.