13 COM ports error: "COM port detected a Receive Overrun Error"

[toko]

Hi,
I got a "COM port detected a Receive Overrun Error" error, when run 14 com ports.
Only com13 had.

My system:
windows XP SP3
Intel Core i5-2400 @ 3.1GHz
2G RAM


DETAILED EVENT LOG
LOG NOTE: 2013-12-17 10:50:27, Status, Main Tests started
CRITICAL: 2013-12-17 10:50:28, Serial, COM port detected a Receive Overrun Error
LOG NOTE: 2013-12-17 10:50:28, Serial, \\.\COM13 Speed: 115200baud BlockSize: 100 BlockNum: 1 Transferred: 100 Handle:00000224 Total: 200
LOG NOTE: 2013-12-17 10:50:28, Serial, 操作順利完成。 (0)
LOG NOTE: 2013-12-17 10:50:28, Serial, Error at byte 12 of 100 (0x4c trans., 0xbe rec'd)
LOG NOTE: 2013-12-17 10:50:41, Serial, \\.\COM13 Speed: 115200baud BlockSize: 100 BlockNum: 2 Transferred: 90 Total: 490
CRITICAL: 2013-12-17 10:50:41, Serial, COM port detected a Receive Overrun Error
CRITICAL: 2013-12-17 10:50:53, Serial, COM port detected a Receive Overrun Error
LOG NOTE: 2013-12-17 10:50:53, Serial, \\.\COM13 Speed: 115200baud BlockSize: 100 BlockNum: 1 Transferred: 100 Handle:000001F4 Total: 690
LOG NOTE: 2013-12-17 10:50:53, Serial, 操作順利完成。 (0)
LOG NOTE: 2013-12-17 10:50:53, Serial, Error at byte 12 of 100 (0xea trans., 0x87 rec'd)
CRITICAL: 2013-12-17 10:51:05, Serial, COM port detected a Receive Overrun Error
LOG NOTE: 2013-12-17 10:51:05, Serial, \\.\COM13 Speed: 115200baud BlockSize: 100 BlockNum: 1 Transferred: 100 Handle:00000384 Total: 1490
LOG NOTE: 2013-12-17 10:51:05, Serial, 操作順利完成。 (0)
LOG NOTE: 2013-12-17 10:51:05, Serial, Error at byte 63 of 100 (0x24 trans., 0x92 rec'd)
LOG NOTE: 2013-12-17 10:51:18, Serial, \\.\COM13 Speed: 115200baud BlockSize: 100 BlockNum: 2 Transferred: 94 Total: 2084
CRITICAL: 2013-12-17 10:51:18, Serial, COM port detected a Receive Overrun Error
CRITICAL: 2013-12-17 10:51:30, Serial, COM port detected a Receive Overrun Error
LOG NOTE: 2013-12-17 10:51:30, Serial, \\.\COM13 Speed: 115200baud BlockSize: 100 BlockNum: 0 Transferred: 100 Handle:000001E0 Total: 2184
LOG NOTE: 2013-12-17 10:51:30, Serial, 操作順利完成。 (0)
LOG NOTE: 2013-12-17 10:51:30, Serial, Error at byte 94 of 100 (0xad trans., 0x3f rec'd)
LOG NOTE: 2013-12-17 10:51:42, Serial, \\.\COM13 Speed: 115200baud BlockSize: 100 BlockNum: 2 Transferred: 99 Total: 2483



com13 and com14 in the same IC, and both have 16 FIFO.
My first question is why only com13 occurred errors, but com14 didn't?
(P.S. at baud rate 9600 is OK)

I log the burnintest commands with LPC bus, I find burnintest test over 16 FIFO, am I correct?

Please Help!!

[Tim (PassMark)]

Serial port overruns are related to a systems inability for the CPU to service the COM port interrupts fast enough, maybe due to blocking by the other devices.

As for why it only affected one port it may be the device driver or underlying hardware chose this is a lower priority to service than the others for some reason.

[toko]

Thank you for your reply.