<t>This is in addition to @DrMoishe Pippik's answer.<br/>
<br/>
Since you are compiling new binaries often, you are effectively showing your antivirus a lot of new programs that it has never seen before. this is in addition to other security mechanisms in place in modern windows, such as SmartScreen.<br/>
<br/>
Several of these mechanisms will first try hash-based detection, which is already a time loss, and when that will come up as a completely unknown binary, will try a variety of other detection methods such as sandboxing and behavior analysis, which take up more time. Additionally, information about or even samples of the binary may be sent to the security solution's publisher, for further analysis and for tracking potential infections with new virus strands. Since this is done over the network, this may take a lot of time.<br/>
<br/>
all of this may be done several times depending on the security tools active, leading to slow downs that are inevitable short of disabling the security measures keeping your machine safe.<br/>
<br/>
Of course, once all of this has happened, the security solutions will be able to identify the binary has already been analyzed and cut their analysis short, which speeds up subsequent execution.</t>
