Solved XMP Necessary for Higher RAM speeds

johnlgalt · Sep 24, 2021

Yeah, for my desktop I went looking for decent XMP, picked the Corsair Vengeance set of 4x 32 GB with XMP == 1798 Freq (so 3600 RAM).

Absolutely happy with them. And I could probably sell them today for 50% more than I paid for them lol, if I were so inclined (I'm not, trust me).

Dru2 · Sep 28, 2021

TairikuOkami said:
I wonder, how many people, who actually bought faster RAM, never activated XMP profile? I say 50:50.

Probably.

For a novice who doesn't want to get into overclocking but does want high speed RAM, they ask the question and become confused by the overclock geek who deep dives, and suddenly things get so muddy the novice isn't touching anything XMP

Yes, "technically" XMP is overclocking the RAM, but we need to remember XMP is nowhere near the "overclocking" that's really associated with the CPU, or even a GPU. Here XMP is a guaranteed boost to get the RAM to its listed specs!

geneo said:
Up to 3200 that is highest jdec, everything above that is XMP.

What RAM do you have? I haven't actually run across any jdec 3200.

I thought the JDEC spec for DDR4 was 2333MHz. Seen anything different?

PerpetualCycle · Sep 28, 2021

Dru2 said:
Probably.

For a novice who doesn't want to get into overclocking but does want high speed RAM, they ask the question and become confused by the overclock geek who deep dives, and suddenly things get so muddy the novice isn't touching anything XMP

Yes, "technically" XMP is overclocking the RAM, but we need to remember XMP is nowhere near the "overclocking" that's really associated with the CPU, or even a GPU. Here XMP is a guaranteed boost to get the RAM to its listed specs!

I thought the JDEC spec for DDR4 was 2333MHz. Seen anything different?

They have updated the spec and rockit lake 11th gen supports it. It is usually at the cost of latency though.

Dru2 · Sep 28, 2021

geneo said:
They have updated the spec and rockit lake 11th gen supports it. It is usually at the cost of latency though.

Yep, latency is usually the cost.

Anyway, have a link for that? I usually like keeping abreast of those things. Thanks.

PerpetualCycle · Sep 28, 2021

Dru2 said:
Yep, latency is usually the cost.

Anyway, have a link for that? I usually like keeping abreast of those things. Thanks.

Try wikipedia?

DDR4 SDRAM - Wikipedia

en.wikipedia.org

Earlier I said > 2400 MHz was overclocking - old info, it can be jdec up to 3200. If it is > 2133 (not 2333 BTW) and says XMP for that speed, it is not jdec.

PerpetualCycle · Sep 28, 2021

CountMike said:
OC seems to be going by the way of Dodo as CPU manufacturers found (more or less) best algorithms to adjust frequency, voltage and all associated parameters for best performance according to load while also attempting to save energy and heat. Manufacturers also included so called "Binning" where they check performance of parts and give them appropriate part number even when those parts are essentially same. That way they can charge more for top performers while not throwing away lesser ones, just sell them for less money although production costs are same.
Before that, you could get lucky at "Silicone lottery" and be able to get more performance by overclocking if possible.

For just those reasons. Silicon Lottery is going out of business in October.

Home

siliconlottery.com

Dru2 · Sep 28, 2021

geneo said:
Try wikipedia?

DDR4 SDRAM - Wikipedia

en.wikipedia.org

Earlier I said > 2400 MHz was overclocking - old info, it can be jdec up to 3200. If it is > 2133 (not 2333 BTW) and says XMP for that speed, it is not jdec.

That thing is clear as mud.

For, me, I'm specifically looking at how the BIOS reads the serial presence detect (SPD) chip on the RAM module to set the RAM's parameters - speed, timings and voltage.

Here the JDEC standard is/was used to set the "initial" RAM parameters. In this example using my own Corsair DDR4 XMP certified RAM @3600MHz. In this example, when I first installed the kit, the initial BIOS setting was 2133MHz speed, timings 22-15-15-36, and a voltage of 1.20. Enabling XMP boosted speed (3600MHz) timings (16-18-18-36), and voltage from 1.20 to 1.350.

Point? Without XMP, my Corsair DDR 4 modules fall to 2133 due to the JDEC standard using in the SPD chip. NOT 3200 or 3600. Now, things may have changed, but for my 2020 RAM, the JDEC used is still 2133. And if I disable XMP in my 2021 F9c BIOS, it will revert back to 2133.

Serial presence detect - Wikipedia

en.wikipedia.org

PerpetualCycle · Sep 28, 2021

Pretty clear to me. Your memory is older, and I believe you need a newer processor - 11th gen Intel, that support the higher jdec speed. Standards and hardware evolve.

Here is Hero z590 (11th gen spec. (OC) means xmp. If there is no OC it is jdec:

You also need memory that supports the higher jdec frequencies.

Dru2 · Sep 28, 2021

geneo said:
Standards and hardware evolve.

You also need memory that supports the higher jdec frequencies.

No kidding. And my system isn't that old as seen in my system specs.

Anyway, I did say this...

Dru2 said:
Now, things may have changed, but for my 2020 RAM, the JDEC used is still 2133. And if I disable XMP in my 2021 F9c BIOS, it will revert back to 2133.

And don't assume I don't know RAM modules have reached higher speeds. My board can handle up to 4400MHz. I'm just running 3600.

Sometimes you come off as being superior. Accept that you're not the only one who knows things.

Peace

PerpetualCycle · Sep 28, 2021

Dru2 said:
Sometimes you come off as being superior. Accept that you're not the only one who knows things.

Peace

Was just responding to your comments to my post with the facts as I know them and did not mean any offense. I won't pretend to not know something. I am a very analytical fact oriented person. I don't think of that as "superior"

We were not talking about higher (OC) RAM speeds llike XMP 4400 MHz, but jdec.

Dru2 · Sep 29, 2021

Yeah... the problem is I'm not convinced of "your facts" as presented, even as I understand "standards and hardware evolve".

I'll move on as the OP has long gotten their answer.

Peace

PerpetualCycle · Sep 29, 2021

Dru2 said:
Yeah... the problem is I'm not convinced of "your facts" as presented, even as I understand "standards and hardware evolve".

I'll move on as the OP has long gotten their answer.

Peace

Well, you asked if I had a link had I provided it. Then you say it is as "clear as mud" so I try and provide information that might help you understand. Then you take offense and insult me.

You reopened the thread after days of inactivity, stating "I thought the JDEC spec for DDR4 was 2333MHz". I was trying to help you undersand that is no longer the case. So yeah, move on. Maybe I should just block you so I don't see your posts, I don't reply, and you don't get offended. Same old same old.

PerpetualCycle · Dec 19, 2021

Sorry for the necro post.

A number of folks in this thread stated that they believe that XMP is not considered as overclocking.

I just came across this on the Intel support thread on reddit. At the bottom of an official response from Intel to someone who was having issues with XMP was the disclaimer:

"Note: The use of XMP profiles is considered a form of overclocking. This may reduce the lifetime of the processor and the rest of the components."

https://www.reddit.com/r/intel/comments/pzn0vw

Also here:

Intel® Extreme Memory Profile (Intel® XMP) and Overclock RAM

Intel® XMP allows you to overclock DDR3/DDR4 RAM memory with unlocked Intel® processors to perform beyond standard for the best gaming performance.

www.intel.com

just passing it along
best

CountMike · Dec 19, 2021

Lol. just trying to save their a$$es in case they shucked something up. Definition of overclocking is clear. Pushing frequency higher than factory tested and found stable.

PerpetualCycle · Dec 19, 2021

CountMike said:
Lol. just trying to save their a$$es in case they shucked something up. Definition of overclocking is clear. Pushing frequency higher than factory tested and found stable.

Well, no, that is not the definition of overclocking. It is pushing the clocks beyond the components' design limits. Do you think they test individual RAM for stability at the factory? I think they just use binned parts that are know for higher quality. And the result also depends on the quality of the processor's Integrated Memory Controller, which can vary considerably when operating out of its design parameters.

High XMP often needs boosted voltages (VCCIO and VCCSA) that are part of the processor chip in order to achieve stable higher speeds. But whether that will have any effect on the life of the processor, IDK, depends on the chip. Sometimes, because of a weak processor IMC, the XMP can not be stable. You are also pumping more current through the IMC and memory which has a degrading effect.

But yeah, most of the time XMP just works, but that CYA is there for a reason. And Intel, who created XMP, considers it overclocking.

CountMike · Dec 19, 2021

XMP is just set of rules/recommendations for BIOS to set itself for particular RAM performance which include frequency as well. Some have 2 XMP profiles (mine has 2400MHz and 3600MHz). Most DDR4 start with 2133MHz effective, 1066.5MHzz real frequency (because it's Double Data Rate). More important part is JEDEC data so why isn't JEDEC settings over lowest frequency overclocking ?

So which of those can be considered OC ? (multiply all of those by 2 for effective RAM frequency).
On top of that when I set XMP (Asus calls it DOCP) on my MB BIOS changes some of those JEDEC and XMP
settings.

Dru2 · Dec 19, 2021

CountMike said:
Lol. just trying to save their a$$es in case they shucked something up. Definition of overclocking is clear. Pushing frequency higher than factory tested and found stable.

Agree. And at the end of the day RAM vendors using XMP DO warrant their products to meet those "XMP" speeds. Corsair offers a lifetime limited warranty on their Dominator Platinum modules running XMP :wink:

And as I said before here's the "difference" where the term overclocking separates - support. And overclocked CPU clocked to 5GHz, where the specs list 4.5GHz is overclocked and not warranted.

On the other hand, though DDR4 RAM is considered overclocked above 2133MHz, RAM @3600MHz with XMP support is warranted and guaranteed to run at.... 3600MHz. Corsair even provides a limited lifetime warranty on this.

In short, XMP is warranted, an overclocked CPU is not!!! And for this reason, I still don't consider XMP overclocking. Yeah, I know the letter of the law, but still... :)

PerpetualCycle · Dec 19, 2021

CountMike said:
XMP is just set of rules/recommendations for BIOS to set itself for particular RAM performance which include frequency as well. Some have 2 XMP profiles (mine has 2400MHz and 3600MHz). Most DDR4 start with 2133MHz effective, 1066.5MHzz real frequency (because it's Double Data Rate). More important part is JEDEC data so why isn't JEDEC settings over lowest frequency overclocking ?
View attachment 16568

So which of those can be considered OC ? (multiply all of those by 2 for effective RAM frequency).
On top of that when I set XMP (Asus calls it DOCP) on my MB BIOS changes some of those JEDEC and XMP
settings.
View attachment 16569

Well, speaking from the Intel side, XMP changes a lot more than that, those are just the most important and shown.

Most people who set XMP leave the Motherboard settings for the voltages Vccsa and Vccio on auto. When you set XMP (which raises the voltage of the RAM above the standard), the motherboard manufacturers jack these two voltages up, as XMP settings may require that to be stable, by more than 30%.. That is more than people raise voltages to overclock the CPU. This normally unnecessary and these voltages usually can lowered to the typical range, but you have to test. These higher voltages could potentially affect the lifetime of the IMC. I am sure when the vendors certify their XMP RAM for specific motherboards, they use these auto settings. There is a bit more going on under the covers than you realize.

Not bashing or saying don't use XMP. Just telling you what Intel says and what is behind some of that.

I don't use XMP, I just use their settings as a guideline and manually set my many of my RAM timings and the voltages. Just so you know I am not bashing XMP or saying not to use it .

Dru2 · Dec 21, 2021

Hi geneo, do you have any reliable evidence pointing to a 30% CPU voltage increase using XMP?

Also realize "Intel" developed XMP so I'd think if it was that harmful to their CPU's they'd not support it. Anyway - What Is Intel® Extreme Memory Profile (Intel® XMP)?

And FYI - Intel XMP 3.0: Memory overclocking gets its first substantial upgrade since 2007

PerpetualCycle · Dec 21, 2021

Dru2 said:
Hi geneo, do you have any reliable evidence pointing to a 30% CPU voltage increase using XMP?

Also realize "Intel" developed XMP so I'd think if it was that harmful to their CPU's they'd not support it. Anyway - What Is Intel® Extreme Memory Profile (Intel® XMP)?

And FYI - Intel XMP 3.0: Memory overclocking gets its first substantial upgrade since 2007

No, I just made this all up

Uh, yeah, just go to any enthusiast forum. It is a well-known practice of motherboard vendors.

Here is what my g.skill XMP 3200 does:

typical values (and values jdec run at) are Vccio = .95 and Vccsa 1.05. XMP is 25% higher for Vccio and 13% higher for Vccsa. I can set the values manually to .95 and 1.05 and it runs fine and is stable. I run stable with even less volts clocked at 3600 than the 3200 XMP (1.12 and 1.16v).
The auto voltages get worse the higher your XMP (your RAM voltage increases the higher your XMP, and these apparently scale with that). Asus even has BIOS settings to limit auto voltages for Vccio and Vccsa (and Vcore) to a user specified cap because of this.