Z97 OC Formula / rig issues.

Glad I could help you with your board, like I said it's not a typical model.

Forgot to tell you, you are not the first person I've helped with the Slow Mode switch issue. But you are the first one that had the nerve to post back and say that was the problem.

About your OC, do you mean you usually leave the CPU voltage settings on Auto, and trust the BIOS and Intel that your CPU will not fry?

You could do the same thing with a high OC, anything beyond 4.5GHz, but you must watch the VCore/VID closely if you run CPU stress tests, or do some gaming that uses the CPU a lot.

Two reasons for that with Haswell processors like yours, both are dangerous for the CPU's life and life span.

First is the heat/processor temperature at high VCore, mainly when stress testing the CPU. Unless you have a custom water cooling system, you can hit 100C in under one minute. I saw that myself with an i5-4670K running AIDA64, the CPU throttled its speed when it hit 100C. Throttling will save the CPU, but who wants their CPU at 100C, that's the boiling point of water, 212F.

Second is using Haswell Adaptive voltage, which is what the Auto setting gives you, and running AVX2 instructions in a CPU stress test. Adaptive voltage is very generous with the VCore. You can enter an Adaptive base voltage, but with the Offset set to Auto, 1.3V can become 1.32V+ while stress testing. If AVX2 instructions are part of the stress test, add another ~0.02V. The higher the base VCore is, the more the Adaptive Offset will add to it.

IMO, a VCore beyond 1.35V is entering the danger zone. Others would say 1.40V, or 1.30V. Depends on the processor too, four core Haswells like yours seem to survive higher voltages than the six and eight core Haswell-E CPUs.

Plus your base clock is 4.0GHz, Turbo is 4.4GHz. My i7-5820K is 3.3GHz base clock, 3.6 Turbo. So my 4.4GHz OC is a 1.1GHz increase from the base clock, or 800MHz beyond Turbo. 4.6GHz is only 200MHz above the Turbo spec for an i7-4790K.

If you see the VCore above 1.3V using Auto VCore settings, try using a fixed voltage.

That is hardly a noob mistake, very few boards have switches like that. The only board I've ever had with those switches is my Z87 OC Formula.

You might also ask why these boards are sent from the factory with the Slow Mode switch set to On. The only reason I can think of is to teach us about it.

You explained your problem with the two cards in the various PCIe slots very well, enough for me to say you really do NOT need both of the eight pin power cables connected to solve your problem.

Take a look at the bottom edge of the board on the left side. Right below the last PCIe x16 slot, and to the right of two gold capacitors is a black rectangle with two silver stripes on each side.

That is a removable cover for a plain four pin molex connector that is used to supply more power to the PCIe slots. That is the PCIe Power Connector. I'm sure the PSU you have now has a spare cable for that connector. Dual eight pin CPU power cables won't cure the PCIe power problem, sorry to say.

That extra PCIe Power Connector is not found on all mother boards, but serves a true purpose. The 24 pin ATX power connector only has TWO +12V connections on it!

Since the eight pin CPU power connector(s) only provides power to the CPU VRMs, and possibly the memory VRMs, those two +12V connections on the 24 pin ATX connector are not enough when using a video card and other PCIe cards.

Dude, you've been paying some dues with that new board. I know what you're thinking... but guess what, now you are no longer a... you know.

The Windows program BIOS/UEFI update tends to be the least reliable, I never use it.

The two options I would suggest are either downloading the Instant Flash BIOS/UEFI update file, or use the Internet Flash option in the UEFI.

The Internet flash option is the easiest, just go to that option in the UEFI and follow the prompts. This option will download and apply the latest UEFI version. If you don't want to use that version, use the Instant Flash method.

For Instant Flash, download the Instant Flash UEFI update file. Unzip it and copy the result to a USB flash drive. Insert the USB flash drive into a USB 2.0 port on the board's IO panel. Then go into the UEFI, go to the Tools screen and find the Instant Flash option. Select it and follow the prompts.

If you still have problems, let us know.

You've got a high end board with several unusual features. If you ever needed to check the manual for a thing or two, this is the board for that.

Your slowness issue is probably caused by the Slow Mode switch being set to on. That switch causes the processor to run at its slowest speed, useful to extreme over clockers. If you would have checked your processor speed, you would have seen it at 800MHz.

The Slow Mode switch is first switch to the left of the Dr Debug display, item 19 in the Mother board layout figure, pages 7, 8, and 9 in the manual.

There are other switches in the same area, so know which one you want to change. If the LN2 Mode switch, to the left of the Slow Mode switch, is set to On, set it to Off.

To be safe, shutdown the PC, disconnect from AC power, and then set the Slow Mode switch to Off. It is common on the OC Formula boards for this switch to be in the On position from the factory.

What method are you using to update the BIOS? Instant Flash, DOS, or Windows?

Are you saying after you update the BIOS and the PC restarts, you get stuck in POST?