In theory it's not but when I choose one of my xmp profiles it changes cpu values including multiplier and locks my cpu on 3.626ghz when it's stock turbo boost is 3.6ghz which is hard to understand..
Also my cpu is 10c more hotter when idle after I apply the xmp profile.
I'm talking about ddr4 and haswell-e cpu on a x99 platform not a conventional system I dont think you know much about it because nobody does still and it was really hard to reproduce this issue over the web (being brand new platform and all)but I found more people that are having the same results and finiding it strange as well.
anyway I sent mail to Asus hoping to clarify why Corsair xmp profiles touches cpu values.
[Edited by kingkob, 11/8/2014 9:51:07 PM]
It's likely increasing the ram controller voltage when it increases the ram voltage to match the given xmp profile. If it also changes the BCLK skew or ratio that could also account for the .026 ghz offset that you see. As far as I know windows only displays one digit after the decimal unless you're using a non-bundled program.
As for win10, unless a game comes out that I just have to have and I decide to upgrade my 3 gtx 470s to a Dx12 card I won't be upgrading. Even if the os only costs $30 I'd still be looking at at least another 300 for a new gfx card. The way games are looking these days I doubt I'll be needing any upgrades in the near future. Never mind that those matte colors just kill my eyes!
In theory it's not but when I choose one of my xmp profiles it changes cpu values including multiplier and locks my cpu on 3.626ghz when it's stock turbo boost is 3.6ghz which is hard to understand..
Also my cpu is 10c more hotter when idle after I apply the xmp profile.
I'm talking about ddr4 and haswell-e cpu on a x99 platform not a conventional system I dont think you know much about it because nobody does still and it was really hard to reproduce this issue over the web (being brand new platform and all)but I found more people that are having the same results and finiding it strange as well.
anyway I sent mail to Asus hoping to clarify why Corsair xmp profiles touches cpu values.
[Edited by kingkob, 11/8/2014 9:51:07 PM]
It's likely increasing the ram controller voltage when it increases the ram voltage to match the given xmp profile. If it also changes the BCLK skew or ratio that could also account for the .026 ghz offset that you see. As far as I know windows only displays one digit after the decimal unless you're using a non-bundled program.
As for win10, unless a game comes out that I just have to have and I decide to upgrade my 3 gtx 470s to a Dx12 card I won't be upgrading. Even if the os only costs $30 I'd still be looking at at least another 300 for a new gfx card. The way games are looking these days I doubt I'll be needing any upgrades in the near future. Never mind that those matte colors just kill my eyes!
I'm using cpuz to monitor.
But Win7 shows me the weirdest thing in properties:
"I75820k @3.30ghz 2.90ghz"
And before xmp profile:
"I75820k @3.30ghz 3.30ghz"
Like my turbo clock is even less than the base clock lol.
Edit: btw it's not increasing ram voltages ddr4 works mostly on a low 1.2v on overclocked speeds.
"DDR4 operates at a voltage of 1.2V with frequency between 1600 and 3200 MHz"
[Edited by kingkob, 11/8/2014 10:09:26 PM]
In theory it's not but when I choose one of my xmp profiles it changes cpu values including multiplier and locks my cpu on 3.626ghz when it's stock turbo boost is 3.6ghz which is hard to understand..
Also my cpu is 10c more hotter when idle after I apply the xmp profile.
I'm talking about ddr4 and haswell-e cpu on a x99 platform not a conventional system I dont think you know much about it because nobody does still and it was really hard to reproduce this issue over the web (being brand new platform and all)but I found more people that are having the same results and finiding it strange as well.
anyway I sent mail to Asus hoping to clarify why Corsair xmp profiles touches cpu values.
[Edited by kingkob, 11/8/2014 9:51:07 PM]
Intels CPUstock valaue for RAM frequency is set to 1333MHz.
An XMP profile is basically a preset value chart on the RAM sticks themselves to make your CPU auto overclock the RAM stock value, to match the actual rated speed of the RAM.
Example;
CPU frequency controller default is set to 1333MHz @ CL9.
Insert RAM rated 2400MHz @ CL10.
Some motherboards will be able to auto detect the RAM max rating for 2400MHz from the XMP profile, in turn auto overclock the CPU RAM controller default value to match that of the stick.
If not,then your RAM would auto underclock itself and you would have wasted a lot of money.
Some other motherboards can not auto do this, you can go into the BIOS and manually try and find and set the XMP profile, or just do all the settings manually with a profile.
This is why it touches CPU values, it overclocks the CPU's memory controller.
Nothing else however.
If the CPU was running @ 3.2Ghz with a boost set to 3.6, these values would still be the exact same, unless you touched the CPU multiplier for some reason.
In theory it's not but when I choose one of my xmp profiles it changes cpu values including multiplier and locks my cpu on 3.626ghz when it's stock turbo boost is 3.6ghz which is hard to understand..
Also my cpu is 10c more hotter when idle after I apply the xmp profile.
I'm talking about ddr4 and haswell-e cpu on a x99 platform not a conventional system I dont think you know much about it because nobody does still and it was really hard to reproduce this issue over the web (being brand new platform and all)but I found more people that are having the same results and finiding it strange as well.
anyway I sent mail to Asus hoping to clarify why Corsair xmp profiles touches cpu values.
[Edited by kingkob, 11/8/2014 9:51:07 PM]
Intels CPUstock valaue for RAM frequency is set to 1333MHz.
An XMP profile is basically a preset value chart on the RAM sticks themselves to make your CPU auto overclock the RAM stock value, to match the actual rated speed of the RAM.
Example;
CPU frequency controller default is set to 1333MHz @ CL9.
Insert RAM rated 2400MHz @ CL10.
Some motherboards will be able to auto detect the RAM max rating for 2400MHz from the XMP profile, in turn auto overclock the CPU RAM controller default value to match that of the stick.
If not,then your RAM would auto underclock itself and you would have wasted a lot of money.
Some other motherboards can not auto do this, you can go into the BIOS and manually try and find and set the XMP profile, or just do all the settings manually with a profile.
This is why it touches CPU values, it overclocks the CPU's memory controller.
Nothing else however.
If the CPU was running @ 3.2Ghz with a boost set to 3.6, these values would still be the exact same, unless you touched the CPU multiplier for some reason.
I finally found the correct answer over the web:
"How does XMP work on DDR4?
Very similarly to DDR3, but with some caveats. For starters, Haswell-E tops out at a 2666MHz memory strap, which is very low for what DDR4 can do. Since XMP specifies speeds in excess of 2666MHz, your motherboard BIOS has to compensate somehow. Typically, when XMP tells the motherboard to use a higher memory speed than 2666MHz, the motherboard BIOS will bump the BClk strap from 100MHz to 125MHz. That’s normal, but that change will also increase the clock speed of the CPU itself; a well-designed BIOS will compensate and bring the CPU clock speed in line."
As you can see it does slightly overclock the cpu, I appreciate your efforts to help but please do a further research next time before Jumping into conclusions.
[Edited by kingkob, 11/9/2014 8:10:11 AM]