Memory Showing Slower Than Rated

I bought a 32Gb kit of Corsair Vengance 2133Mhz memory (4x8Gb) from Amazon. Box showed up, factory seal, memory inside was unblemished, it had never been used.

I installed it in my Gigabyte X79-UP4 motherboard (Rev. 1.1 with BIOS F7) using their instructions (slots 1 & 2 in bank 1, slots 2 and 4 in bank 2). Their manual and website both say the Rev. 1.1 board can handle 2133Mhz memory. Its the fastest it can take.

The processor is a Intel i7 3930K.

No matter what metric I use, Speccy or CPU-Z, the 2133Mhz memory is reading 656Mhz. That's lower than the 1066Mhz that was in there previously.

I have pulled, cleaned the slots of any dust, reseated the memory, twice. Checked the BIOS settings and Gigabyte's manual and support forum. Nothing, I can't get it to read 2133Mhz.

I'm at a loss at this point. Can anyone help, maybe steer me in the right direction or a suggestion? It would be greatly appreciated.

Thanks.

Do you have XMP turned on in BIOS?

Arelem said:

Nope, because the manuals said nothing about having to change anything to use what they listed as supported memory speeds.

try it

You need to turn it on, to use RAM higher than your CPU's "guaranteed will work" clocks.
For your CPU that's only:

Intel Coreâ„¢ i7-3930K Processor (12M Cache, up to 3.80 GHz) Product Specifications

But if your motherboard allows higher, through XMP, you need to turn it on,
If you find it makes changes to your CPU's OC settings(on some motherboards it raises Vcore, or makes a small change to your base clock, some boards not), just write down ALL the setting pertaining to RAM, turn off XMP, then manually set it.

Arelem said:

Cool, thanks for the heads up. I'll try it and get back to you :)

OK:)

Be aware that whenever you update a BIOS it's also best to load optimized defaults or whatever it's called on your board, even if you are planning on tweaking things later. Also bear in mind that most boards will have XMP disabled by default; especially true after a BIOS update.

Good luck.

Due to JEDEC specs, RAM running above certain frequencies (in the case of newer systems 2133MHz) are considered to be overclocked, thus the need for XMP. And if you look at the RAM specs of today's CPU's (NOT the MB), you'll see the JDEC spec, not the maximum spec. Here's my i7-7700K - Intel Coreâ„¢ i7-7700K Processor (8M Cache, up to 4.50 GHz) Product Specifications

Notice it says 2133 for DDR4, and 1333 for DDR3. However my motherboard supports RAM up to 3600MHz. I'm running modules that run at 3333MHz and either need to set them manually to run at those speed, or Enable XMP. Also note that RAM modules pushed to their "overclocked" spec, will also need their voltage upped. My RAM for example runs at 1.2 volts at 2133, but needs 1.35 volts to run at its stated speed of 3333MHz. You can see this by looking at CPU-Z's SPD tab.