Why am I seeing poor performance on Windows
XP when I use multiple USB serial interfaces?
Windows XP system performance may be reduced when multiple USB-
232 and USB-485 devices are installed. This can cause slow screen
updating (mouse and window movements) and reduced task switching
performance. This problem is addressed in Windows XP Service Pack 1.
To obtain Windows XP Service Pack 1, use Windows Update, or contact
Microsoft at www.microsoft.com.