CPUs maximum Voltage + MHz tolerance.

[TNTee]

I made an inquiry yesterday at intel's official site...asking about what would be the maximum safe voltage of RAM tolerated by the i5-2500K specifically... and anyway this is the conversation:

j.ei-kay@hotmail.com: hello there
Daniel: Hello. Thank you for using the Intel Customer Support chat service. We are glad to be of service. How can I help you today?
j.ei-kay@hotmail.com: well i have a question
j.ei-kay@hotmail.com: regarding the voltage that socket 1155 intel i5-2500k can tolerate
j.ei-kay@hotmail.com: the voltage of RAM that is...
j.ei-kay@hotmail.com: what is the maximum voltage that the RAM has to be in order for the processor to be...safe
j.ei-kay@hotmail.com: ?
Daniel: Since the memory controller is built into the processor, it will take a maximum of 1.5V DDR3 1066 1333 Mhz
j.ei-kay@hotmail.com: what?
j.ei-kay@hotmail.com: maximum of 1333 MHz of RAM ?
Daniel: correct, check the following website:
Daniel: http://ark.intel.com/Product.aspx?id=52210&code=Intel%c2%ae+Core%e2%84%a2+i5-2500K+Processor+(6M+Cache%2c+3.30+GHz )
j.ei-kay@hotmail.com: i thought the processor was refering to gamers and pc enthusiasts in general :S
j.ei-kay@hotmail.com: hmmm ok...let me ask something else then..
Daniel: go ahead
j.ei-kay@hotmail.com: what happens if i use a 1.5v of higher frequency?
j.ei-kay@hotmail.com: it simply won't do any difference on performance?
j.ei-kay@hotmail.com: make any difference*
Daniel: you will damage the memory controller on the cpu, the system will stop working eventually
Daniel: you will cause damage to the system when using memory rated at higher voltages
j.ei-kay@hotmail.com: but like i said
j.ei-kay@hotmail.com: it will be 1.5v
j.ei-kay@hotmail.com: the frequency alone..will be higher
j.ei-kay@hotmail.com: that would still dmg the processor?
Daniel: ?
Daniel: Again,
Daniel: you can only use 1.5V, not higher or lower, plain 1.5V rated memory exclusively..
j.ei-kay@hotmail.com: mate...the voltage will BE 1.5 v
j.ei-kay@hotmail.com: but it will be 1600 MHz
j.ei-kay@hotmail.com: or 2000 MHz
Daniel: sorry but that will not work, the controller will operate at 1333MHZ or not operate at all
Daniel: we don't recommend that , is up to the customer's risk
j.ei-kay@hotmail.com: uhuh...does intel actually have a processor able to handle 2400 MHz anyway?
j.ei-kay@hotmail.com: no need to point out a specific one..
Daniel: no.
j.ei-kay@hotmail.com: ok ok.. well then all the companies that actually create RAMs and specifically mention that are compatible and even especially made for the 2nd generation intel processors...
j.ei-kay@hotmail.com: but function at higher frequencies than the CPUs
j.ei-kay@hotmail.com: what would be the point?
Daniel: I will suggest forwarding your inquiry to the different memory manufacturers.
j.ei-kay@hotmail.com: uhuh..i understand
j.ei-kay@hotmail.com: i ll do that

I was quite socked to see that he said something like "sorry but that will not work, the controller will operate at 1333MHZ or not operate at all "...that means that if you use any differently MHz frequenced RAM the system will fail and not work. I mean while searching for the best DUAL RAM-kit possible for gaming use...i've never been told or read anything about that part...everyone suggested 1600 MHz ++ without any mentioning anything about that. How true is what he told me actually? I mean i'm already sure that my warranty will go void if i don't "play by these rules" ...but still if it's perfectly fine to abide these rules and use what's actually best for performance (without killing my rig and having malfunctions of course)...then the hell with that.

 

[hunter315]

The memory controller is on the CPU so its got tighter specs than the ones on the northbridge used to, it is only promised to work perfectly up to 1066, it will likely work just fine at 1600MHz but they wont promise that it wont throw a single bad bit once in a while.

As for the voltages, its unsafe to use RAM at more than 1.65V in an intel system these days, its best to keep it lower, around 1.5V because there have been reports of IMCs burning out when only set to 1.65V.

 

[Haserath]

You can run 1600-2400mhz ram if the processor is able to. You would have to keep the ram voltage within a safe voltage limit to keep the memory controller safe, but it could run at those speeds.

The old i7 generation would run 2000mhz+ ram as long as the memory controller got enough voltage even though Intel only suggests 1066mhz memory.

There really isn't any point in getting memory faster than 1333mhz, because the processor doesn't even use all that bandwidth in the first place. With multiplier overclocking, you might as well get the cheapest ram of good quality you can find and just get more of it, or use the money saved to buy other parts. People used to get 1600mhz+ ram, because they had to worry about the ram getting overclocked when they were overclocking their core speeds.

 

[TNTee]

What do you mean by:

You can run 1600-2400mhz ram if the processor is able to

how do you find out how much MHz the processor can tolerate for real? I mean the only idication you get is the one mentioned on intel's official site which is REALLY low if you ask me...

 

[Haserath]

What do you mean by:

You can run 1600-2400mhz ram if the processor is able to

how do you find out how much MHz the processor can tolerate for real? I mean the only idication you get is the one mentioned on intel's official site which is REALLY low if you ask me...

You're basically overclocking the memory controller to reach those speeds. The new 2xxx series only goes up to 2133mhz, I believe.

It's impossible to know what the cpu can actually tolerate, each one is different. Intel's spec is the 100% guaranteed spec that the processor can run ram at(well, if it doesn't then Intel would have to replace yours, some bad ones get out).

 

[TNTee]

By memory controller you mean the CPU's memory controller right? Do you overclock it via the CPU's BIOS?

 

[Leaps-from-Shadows]

Intel's specification only goes up to 1333MHz. However, most overclocking boards can set the BIOS to 1600, 1866, and 2133 speeds for RAM as long as the RAM itself can run at that speed. You should still stick to 1.5v RAM if possible, because higher voltages really can burn the memory controller on the CPU.

Edit: You'll never get a straight answer from any Intel employee. They can only tell you what the official specs are. The company may allow you to choose to overclock, but they don't actually officially support it.

 

[TNTee]

Ok so here is the main idea...i should get 1.5v RAM-kit of at least 8GB with Highest frequency possible and with best possible timings...in that exact order of importance for performance and system stability.Correct?
I'm thinking of buying RAM that make use of intel's XMP technology...does XMP actually also affect the voltage if i choose a different SPD profile other than the default? and something else...my ASUS P8P67 Pro supports these frequencies: 2200 (OC) // 2133 (OC) // 1866 (OC) // 1600 // 1333 // 1066 so wherever OC is mentioned that means that i have to manually configure the frequencies through its BIOS? or that there are automatic choices of those frequencies you can choose that are still considered OC-ing anyway? Also...there is this reference about the RAM slot frequencies as well: "Due to CPU behavior, DDR3 2200/2000/1800 MHz memory module will run at DDR3 2133/1866/1600 MHz frequency as default." What's that about...can't i take full advantage of a 2200 MHz RAM-kit for example? (if we hypothetically use a 1.5v of course on those MHz..since i doubt there is one)

Here are some RAM i m considering by the way...
- Vengeance 2x4GB 1866MHz (CMZ8GX3M2A1866C9)
- Vengeance 2x4GB 1600MHz (CMZ8GX3M2A1600C8)

 

[Leaps-from-Shadows]

Your links are broken.

Sandy Bridge CPUs can only do 1333, 1600, 1866, and 2133 RAM speeds. If you buy any other speed of RAM, it will clock down to the next nearest supported speed.

XMP should set the speed, timings, and voltage to whatever the manufacturer programmed in.

And yes, if you want the extra few percentage points of performance, get the highest possible speed and lowest possible timings on a 1.5v RAM kit. The best price/performance ratio is found at 1600MHz. Buy a nice 1600 CL8 1.5v kit and you're golden.

 

[Haserath]

Don't spend too much on RAM, it really doesn't make much of a difference in real life programs. If you can get more RAM then get that instead of faster RAM.

XMP could possible affect the voltage if they profile is made to do so, but the stated voltage is the highest voltage it will go if it's rated 1.5V that will be the highest voltage it will go.