Memory, CPU and mobo question

[Griffscavern]

OK I'm getting a Asus z97-ar mobo. It will support up to 3200 MHz ram, but I am also getting a i7 4790k CPU. When I try to go for any memory over 1.5 volts, it says my CPU may ramp the memory down. Why is this? Will xmp enabled on my mobo override this?

 

[MeteorsRaining]

XMP is present for that particular purpose. It allows Memories to work at Frequencies (and voltage) above the recommended 1.5V limit. Your MoBo will take care of voltage once XMP is enabled.

 

[thx1138v2]

XMP might override it. The following is from the ASUS Memory section of their specifications page for that mobo.

"* Hyper DIMM support is subject to the physical characteristics of individual CPUs."

"Hyper DIMM" is the ASUS name for their implementation of Intel XMP. So that statement means what XMP will support is dependent on the exact actual CPU installed. I haven't seen any explanation of what exactly the XMP support relies upon.

Scroll down to the Memory section at the following link
Z97AR Specifications

 

[Griffscavern]

Thank you MeteorsRaining. It just always baffled me that I had so many options for memory on this mobo, but was limited by the CPU to half of what is possible.
This will be my first build in 10 years. Never got to put finishing touches on furst build. Haven't had a comp for 4 or 5 years. So relatively new at this. Been researching and updating my memory for a month now. Want all my ducks in order before I pull the trigger on this build. Looking forward to having an ssd, pci-e cards, sata 3. Those were not available 10 or 11 years ago. Pci-e was just up and coming then.

 

[Griffscavern]

Quote:

XMP might override it. The following is from the ASUS Memory section of their specifications page for that mobo.

"* Hyper DIMM support is subject to the physical characteristics of individual CPUs."

"Hyper DIMM" is the ASUS name for their implementation of Intel XMP. So that statement means what XMP will support is dependent on the exact actual CPU installed. I haven't seen any explanation of what exactly the XMP support relies upon.

Scroll down to the Memory section at the following link
Z97AR Specifications

End quote.

I see what you mean. I read the same thing, but was hoping for something other than what I though it was saying. From the looks of it, I am stuck with only memory that is 1.5 volts. Most of the ram over 1866 is above this voltage. So i will probably be going with 1600 mhz with a cls of 8. Otherwise I'd just be wasting money.

 

[MeteorsRaining]

I'd strongly say most 1.65V modules with XMP will be accommodated well. 'MemOK' buttom will ease up the task even more. If you want to go with freq higher than 1600Mhz, then by all means go.

XMP (Extreme Memory Profile) is basically a non-JEDEC approved SPD table for your RAM that is programmed into the sticks. By setting XMP you can run the sticks at their RATED (>1600Mhz) speed and timings even if it requires more voltage to do so.

XMP is provided by Intel itself, and if the stick says it supports 'XMP' and the MoBo says so as well, and the stick is within the supported freq (OC), then it will be compatible.


"* Hyper DIMM support is subject to the physical characteristics of individual CPUs."

^The statement is interpreted wrongly in above posts. By that, manufacturer is referring to a relation between the BLCK of the CPU and the DIMM freq. The CPU base freq is directly related to BLCK, and some CPUs (with lower clock speeds) might not allow high bandwidth sticks (>2400Mhz) to have stated timings, they might loosen them. This happens mostly when one is trying to combine, say a Pentium (w/o OCing) with a 2800Mhz stick. But your CPU has 4.4Ghz freq with boost which's fine for the high bandwidth sticks.

 

[Tradesman1]

Most all 4790K can run up to 3200 DRAM, for most DRAM 1600 and above you enable XMP and the sticks will set themselves up - for data rates of 2400 and up it often takes a slight OC of the CPU. I run 32GB of 2800 on one of my 4770Ks (the 4790K has a slightly stronger MC (memory controller), on my other 4770K I have 32 of 2666. 2133/2400 is sweet spot for price/performance on the 1150 with a K model CPU

 

[MeteorsRaining]

Most all 4790K can run up to 3200 DRAM, for most DRAM 1600 and above you enable XMP and the sticks will set themselves up - for data rates of 2400 and up it often takes a slight OC of the CPU. I run 32GB of 2800 on one of my 4770Ks (the 4790K has a slightly stronger MC (memory controller), on my other 4770K I have 32 of 2666. 2133/2400 is sweet spot for price/performance on the 1150 with a K model CPU

+1

Very high bandwidth memory (like the one you wish to get), will require a bit of OC.