Hello guys, I believe I have had som luck finding solutions for several issues with the DX79SI motherboard. I hope these tricks works as well for you.
First of all PCIe 3.0 works well with my Nvidia 670 GPU. The trick is to use the uppermost PCIe slot on the board. This slot is not shared and has no lane switches. Perhaps the lane switching IC's creates noise on the bus? Nvidias own control panel confirms that PCIe 3.0 is active after having run the force-enable-gen3.exe tool. I have stress tested the card using Furmark. No problems so far.
Secondly, my Kingston HyperX memory modules are working perfectly now at 2133 MHz. Apparently the DX79SI board uses the wrong CAS write latency timing. It always sets a Tcwl timing of 8 ?! The modules XMP settings however says that a timing of 10 should be used. It's an easy fix to use manual settings and the AUTO value for Tcwl. Or manually setting to 10 of course.
There have also been problems with Intels 520 SSD's. They always seem to crash when I use the SSD Optimizer in the Toolbox. In RAID mode at least. I seem to have solved the problem though. Simply use the "high performance" power setting in Windows 8. This disables DIPM on the SATA interface. After that, there have been no lock-ups so far.
I only have 2 outstanding issues now. One is the lack of Smart Response Tech in the RSTe drivers. With Asus, Asrock or Gigabyte boards you can fix it by Switching to the RST OROM in the BIOS. On the Asus boards you do that by using UEFI boot. With Asrock you just select it in the BIOS.
Why can't you do that with the DX79SI? It must be a BIOS issue.
My last issue is the lack of support for Windows 8 secure boot. You can use UEFI boot and Windows 8 with the DX79SI, but the system information shows that secure boot is not supported. Secure boot works well with Asus boards using the same chipset, so it must be a BIOS issue?
Overall I'm now pleased with the system though.
I installed win 8.1 and it doesn't take Bluetooth drivers the drivers get installed but it stops showing on the system task bar after a restart... And also when the computer boots it doesn't show the boot options like f2,f10,f7 etc... So what has to be done in that case...
Thank you for joining the Intel communities.
We appreciate the information you have shared with us mjoelner.
What operating system version do you have installed?
Have you try with the latest https://downloadcenter.intel.com/download/23825/BIOS-Update-SIX7910J-86A- BIOS version?
You can follow the steps to install the latest BIOS here:
http://www.intel.com/support/motherboards/desktop/sb/CS-030144.htm Desktop Boards — Instructions for F7 BIOS Flash Update
Make sure you have Windows up to date and to install the latest drivers from the Intel website:
https://downloadcenter.intel.com/product/55799/Intel-Desktop-Board-DX79SI Downloads for Intel® Desktop Board DX79SI