z97 extreme9 networking problem

I have noticed file transfer corruption under certain conditions:
1. When the extreme9 is the source of the data copying 1 file of known SHA256 hash to either destination machine, the SHA256 on either destination machine after copying is in error.
2. When the extreme9 is the destination of the data copied from either source machine, there is no error.

It is as though the extreme9 can't write to the LAN without data corruption. It can read from the LAN fine.

I also connected the same LAN cable to an Asix A88772B-based USB<->Ethernet adapter (only 100Mbs-1) and this transfers in either direction without error.

This points to something odd (either hardware or driver I guess) in the path from the RJ-45 LAN connectors to the PCI express bus into the z97 chip via either of the Intel LAN chips, but I'm kinda stuck at this point as to how to debug the problem further.

Any advice much appreciated.

OS = w7x64
All drivers up-to-date (today), devmgmt.msc no unknown drivers.
disk = intel SSD750 400MB
cpu = i7-4790K
4x8GB ddr3-1600
using IGP to drive 4k display

I like your lateral thinking, but unfortunately a test with the USB-stick as source also gives a SHA256 error. I have also tested with SATA3 SSDs and an Ultra II SSD in a USB30 enclosure as sources and both of these result in SHA256 errors.

Only file transfers appear to be an issue, PINGs and VNC sessions between machines are working.

To summarise, regardless of whether the storage is PCI-E SSD, SATA3 SSD , SanDisk stick or USB30 SSD
extreme9 <- gryphon =PASS
extreme9 <- laptop = PASS
gryphon <- extreme9 = FAIL
gryphon <- laptop = PASS
laptop <- extreme9 = FAIL
laptop <- gryphon = PASS

I will likely experiment further once I lay my hands on a PCI-E network card. Will report back later today.

5. Wired or wireless connection(s)? Again, I know. I know.

Right, answers to questions...

These are simple file copies, so Windows Explorer, sometimes fastcopy just to double-check it's not a Windows  Explorer bug. I'm using mapped drives for the copies, not UNC paths. I'm using 2 files both VirtualBox setup EXEs (so compressed). After copying, the generated SHA256s appear random, there's no pattern to the after-copy SHA256s. NIC driver (19.0.27.0) was downloaded from the  z97 extreme97 w7x64 downloads page of the AsRock website from the USA link as this is HTTP, the Europe one is FTP.

Wired, CAT-6A 3m STP cable.

No AV. I test with and without VNC sessions just in case, but it makes no difference.

I now have a PCI-E NIC to try out (chip is Realtek RTL8168B) so will run more tests and update in a couple of hours.

Here, first lets rule out old network drivers. Occasionally older NIC drivers will butt heads with new(er) programs and or system files.


Much much newer I211-AT NIC/PHY drivers from:
https://downloadcenter.intel.com/product/64404/Intel-Ethernet-Controller-I211-AT

So you're aware, these will also unlike the drivers from ASRock(last I checked) also install Intel's PROSet utility.


Edited by wardog - 29 Jan 2016 at 3:21am