I've lurked around this forum now and then, but spend most of my time at Overclock.net. Thought I'd ask here for advise for my problem.
My 1st PCIe slot is stuck at x4 native no matter what I do. My system is up and running fine and while I was in the bios I noticed under Advanced\System Agent Config\NB PCIe Config it shows slot 1 "Running at x4 Native".
The second slot showed the x8 Native. I was surprised by this, so I checked Aida64, CPUz and GPUz all show x4.
This is a new build here is the component list:
Asus Maximus Formula VI Motherboard Bios 1102 (now 1203)
i7-4770k Haswell
Corsair H110 CPU cooler
Corsair 860i power supply
2 x Samsung 840 EVO 250 GB (no RAID)
Seagate 4 TB hard drive
G.SKILL Trident X Series 16GB (2 x 8GB) 2666
2 x XFX Double D Radeon 7950 Black Edition 3GB in Crossfire
Creative Sound Blaster ZXR (now removed)
Windows 8.1Pro
Here is the list of what I've tried already:
1. Checked for bios update, when I first built the system I updated to the most recent which was version 1030 (not positive on the number), just a few weeks later there is version 1102, and the original update version I used was not listed anymore. So I updated to the most current version 1102. Still only shows x4. Updated to the brand new bios today version 1203. Still only shows x4.
2. In the bios under Advanced\System Agent Config\NB PCIe Config, changed both cards from "Auto" to "Gen 3". Still only shows x4.
3. Removed the lower gpu, still only shows x4.
4. Switched power cable from power supply to the top and only card, still only shows x4.
5. Removed the gpu from the top slot and put the one that was in the lower slot in the top slot, still only shows x4. Note: I purchased the two graphics cars from two different venders several weeks apart, so very unlikely to be a bad batch of cards.
6. Removed the Creative Sound Blaster ZXR card that was installed in the top x1 slot above the top PCIe slot, still only shows x4.
7. Removed the Blue tooth / Wireless card, still only shows x4.
8. Reset the CPU, still shows x4.
I have done a lot of research on this and I have found at least half a dozen other people that have had this problem. However I never found a solution. My feeling is that it is either a bios problem or motherboard problem. The only other possibility I have found is the CPU, but I feel this is highly unlikely.
I did run some Heaven 4 benchmarks with these settings, custom, direct x 11, ultra, extreme, AA x8, full screen, 1920 x 1080.
Here is with one card in the top slot:
FPS 30.5
Score 769
Min FPS 17.3
Max FPS 65.8
With both cards in:
FPS 60.1
Score 1513
Min FPS 29.3
Max FPS 130.3
Everything is about double with both cards installed, so it seems to me that everything is working fine. I did spend a lot of money on all the gear and would really like it to function to the fullest extent that it should, however I don't want to be down 4-6 weeks waiting on a board RMA (not sure how that works, never had to RMA a board).
I saw a chart some place and cannot find it at the moment, but it showed the difference between a PCIe 3.0 x4 and PCIe 3.0 x8 is only 1% in performance.
This is not my first build, but it is my first ROG board. I'm hoping there is something in the bios or a silly setting some place that I'm unaware of. I really do not want to RMA the board unless I have to.
Please advise me and thank you in advance for any assistance.
Barefooter
