I am running into a wierd performance issue whereby a DMA engine on the PCIE bus is getting sginificantly lower performance under Linux then Windows on a dual boot platform. We are using a performance test that builds a descriptor list that sends up to 4 Gigabytes of data before interrupting in order to isolate the issue to the DMA engine itself. So we are sure that the cause is not do to interrupt latency as the performance remains the same if the performance test interrupts after every 4 MB of data (one transaction) or 4 Gigabytes of data (1000 transactions before interrupting. The most plausible explanation I have heard is that Linux is responding to bus errors being reported via the advanced error reporting capability as it is PCIE aware and Windows is ignoring the errors, however I have tried to rebuild the kernel with error reporting turned off, and I have also masked out the interupt reporting in the device itself. Can anyone point me to a good system hardware analysis tool that runs under Linux OpenSUSE that can shed light on what may be causing this issue?