'EndXfer' Affects speed

[tianyaQQ]

session.DGControl.PendingXfers.EndXfer(pending);// 0.3 seconds slower

In the Win7、canon6030c, when the scanner parameter size is set to automatic detection, it is 0.3 seconds slower than setting a fixed size. As the number of scans increases, there is a significant delay in obtaining the last image. How can this be solved?
Computers with good Win10 performance have less noticeable latency.

static class TransferLogic
{
///

/// Performs the TWAIN transfer routine at state 6.
///

public static void DoTransferRoutine(ITwainSessionInternal session)
{
...
if (rc != ReturnCode.Success && session.StopOnTransferError)
{
// end xfer without setting rc to exit (good/bad?)
session.DGControl.PendingXfers.Reset(pending);
}
else
{
rc = session.DGControl.PendingXfers.EndXfer(pending);
}
}