CPU RAM RATINGS

[Watashi]

Why does is the intel i7 6700k only rated for ram speeds of 2133 Mhz if you can use higher speeds of ram without OC'ing it?

[Enderman]

You need to enable XMP if you want the ram to run at higher speeds.

[SLAYR]

2 minutes ago, Doomerson said:

Why does is the intel i7 6700k only rated for ram speeds of 2133 Mhz if you can use higher speeds of ram without OC'ing it?

That is what Intel tested with that cpu, you should be able to up to 4+GHz on the ram if your motherboard supports it.

[Watashi]

6 minutes ago, Enderman said:

You need to enable XMP if you want the ram to run at higher speeds.

I do know this. What XMP stand for?

[Enderman]

2 minutes ago, Doomerson said:

I do know this. What XMP stand for?

Extreme memory profile.

Aka overclocked memory.

[typographie]

2133 MHz is part of the JEDEC specification for DDR4 memory. Anything beyond that is treated as an "overclock" and out of spec, even though the DIMMs, CPUs, and motherboards will usually tolerate a lot more. So, the memory manufacturers usually include an XMP profile for a nominally tested and supported set of overclocked settings for that product.

[Watashi]

4 hours ago, typographie said:

2133 MHz is part of the JEDEC specification for DDR4 memory. Anything beyond that is treated as an "overclock" and out of spec, even though the DIMMs, CPUs, and motherboards will usually tolerate a lot more. So, the memory manufacturers usually include an XMP profile for a nominally tested and supported set of overclocked settings for that product.

So a stick of ddr4 RAM that runs at 2400Mhz (after xmp is activated) is actually a 2133 stick that is over clocked?

[faziten]

3 hours ago, Doomerson said:

So a stick of ddr4 RAM that runs at 2400Mhz (after xmp is activated) is actually a 2133 stick that is over clocked?

No. Your ram is made out of a PCB and memory modules. Those memory modules have a rating. Lets say 3000Mhz. The JDEC inside the CPU specification goes up to 2133 Mhz, but your motherboard allow you to access the memory faster, if the memory can support it. So in that regard you are asking the ram: Hey what are the speed settings i can use you? (Enabling XMP), then the ram will give you a list of every possible speed it can be set to if it has an XMP profile. You choose whatever speed you want and then the motherboard does all the magic tricks to the Factor multiplier so your cpu can access it full speed. 

 

Will it be always possible? No.

1) Your ram Must have an XMP profile.

2) Your motherboard should let you select an XMP profile for the ram. (Any good brand motherboard should let you do it). 

3) Your CPU memory controller should be strong enough. Which is the case of Skylake so no worries there.

 

Enabling XMP does NOT overclock your CPU. It does "overclock" the RAM but it does in a pre-tested by the manufacturer way. So no warranty voiding here whatsoever. 

If the modules are rated at 2800Mhz, you are guaranteed to hit that given your Motherboard can do it. It's not the same as buying 2133 modules and crossing fingers to reach 2800Mhz manually overclocking (which is possible if you are lucky enough). 

[Watashi]

1 hour ago, faziten said:

No. Your ram is made out of a PCB and memory modules. Those memory modules have a rating. Lets say 3000Mhz. The JDEC inside the CPU specification goes up to 2133 Mhz, but your motherboard allow you to access the memory faster, if the memory can support it. So in that regard you are asking the ram: Hey what are the speed settings i can use you? (Enabling XMP), then the ram will give you a list of every possible speed it can be set to if it has an XMP profile. You choose whatever speed you want and then the motherboard does all the magic tricks to the Factor multiplier so your cpu can access it full speed. 

 

Will it be always possible? No.

1) Your ram Must have an XMP profile.

2) Your motherboard should let you select an XMP profile for the ram. (Any good brand motherboard should let you do it). 

3) Your CPU memory controller should be strong enough. Which is the case of Skylake so no worries there.

 

Enabling XMP does NOT overclock your CPU. It does "overclock" the RAM but it does in a pre-tested by the manufacturer way. So no warranty voiding here whatsoever. 

If the modules are rated at 2800Mhz, you are guaranteed to hit that given your Motherboard can do it. It's not the same as buying 2133 modules and crossing fingers to reach 2800Mhz manually overclocking (which is possible if you are lucky enough). 

This was truly a great explanation. Thank you much! That answered a lot of questions I had. I feel like using a RAMs xmp is similar to having a factory over clocked gpu.

[typographie]

9 hours ago, faziten said:

No. Your ram is made out of a PCB and memory modules. Those memory modules have a rating. Lets say 3000Mhz. The JDEC inside the CPU specification goes up to 2133 Mhz, but your motherboard allow you to access the memory faster, if the memory can support it.

Maybe I'm misunderstanding you, but I don't think the DIMMs or the memory chips on the DIMM can be "rated" for 3000 MHz. I don't think they could be sold in compliance with the standards if they were actually rated that way. That's still technically 2133 MHz memory, it just includes a tested (and ideally guaranteed) 3000 MHz settings profile which requires user intervention to enable, and therefore they can maintain their standards compliance.

 

8 hours ago, Doomerson said:

This was truly a great explanation. Thank you much! That answered a lot of questions I had. I feel like using a RAMs xmp is similar to having a factory over clocked gpu.

I don't think that's a bad analogy. The difference is that usually the GPU will come with the overclocked settings already enabled (usually), whereas XMP is always disabled until you turn it on.

[Frank98]

I need you're guys' opinion. Should I get a RAM card if I already have a 4GB graphics card? And also the graphics card that I plan on buying is the AMD Radeon RX 470 with the ASUS M5A99 FX Pro R2.0 motherboard. Would anybody recommend those two together?

[Watashi]

2 hours ago, Frank98 said:

I need you're guys' opinion. Should I get a RAM card if I already have a 4GB graphics card? And also the graphics card that I plan on buying is the AMD Radeon RX 470 with the ASUS M5A99 FX Pro R2.0 motherboard. Would anybody recommend those two together?

what kind of socket does the motherboard have? Also every computer needs RAM sticks, I've never heard of a "RAM card"