In response to the "engineer's update" from earlier this month, they made a mention of this:
Now, I believe that my computer is encountering the same issue - I've been experiencing unexplained USB-to-display input-lag for over a year now and I've exhausted every possibility I can think of - but this recent update to the thread made me wonder how I can have access to PCI Express bus retransmit stats - surely this must be exposed through some low-level hardware functionality such as at least a JTAG port, or through SMBus?We don't know what specific slowdowns were caused by -- flood of IRQ interrupt noise or error-correcting behaviours on SATA cables or noise on ECC DRAM buses or some other mysterious EMI-based slowdown effects, or a PCI Express bus trying to retransmit data during noise errors -- probably error correcting by the millions, like death by a million nanoseconds or microseconds that added up to continually visible slowdowns (game stutter, Window-dragging stutter, scrolling stutter, etc). Even when nothing was running in background (CPU/GPU near 0%), and scanners found no viruses.
I took a look through Windows' Performance Counters in the PerfMon MMC snap-in but I didn't see anything relevant to PCI Express at all.