Max RAM speed with Ryzen without entering overclock mode?

wchang99

Member
Jul 14, 2000
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Definitely a noob question.

What RAM speed can you get with Ryzen without entering overclock mode? Suppose you have 3200MHz/CL16 -rated RAM (single-rank, 2 DIMMS). Is anything above 2133 MHz going to involve being in overclock mode, thus disabling Precision Boost and XFR?

Or is 2667 MHz (the AMD official max supported speed) the limit above which you need to be in overclock mode?

Or can you always toggle between 2133 and your memory's rated speed (just those two speeds) without entering overclock mode?

(I don't plan to overclock my CPU, so don't want to be in overclock mode just for RAM if it means losing Precision Boost and XFR. And if I'm not going to be in overclock mode, I'm wondering if I should buy faster RAM like 3200MHz/CL16 or if that extra RAM speed would never be used.)

Many thanks -- definitely appreciate it.
 

JimmiG

Platinum Member
Feb 24, 2005
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2667 is the maximum that's "officially" supported by AMD per the official powerpoint slides. However using faster memory will not disable turbo boost or XFR.

It's not the same as overclocking the actual core clock. You're only overclocking the Infinity Fabric, which actually provides a big performance boost, especially in games. It's completely transparent and automatic when you activate the XMP profile and set a faster memory clock. It might however require a very small boost to the SOC voltage (not VCore voltage) in your BIOS setup.

When buying RAM, I recommend you get 3200 CL14 or faster, in order to make sure you get Samsung B-die memory. 3200 CL16 and slower tend to be E-die or Hynix, which does not work as well with Ryzen.
 

wchang99

Member
Jul 14, 2000
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Nop. If tou change the RAM Clock, you automatically overclock the Uncore in 2:1 reason. Because of that, Ryzen goes to OC Mode.

Thanks. I'm still reading up on the terminology and how some of this works, and appreciate your help.
 

wchang99

Member
Jul 14, 2000
107
4
81
2667 is the maximum that's "officially" supported by AMD per the official powerpoint slides. However using faster memory will not disable turbo boost or XFR.

It's not the same as overclocking the actual core clock. You're only overclocking the Infinity Fabric, which actually provides a big performance boost, especially in games. It's completely transparent and automatic when you activate the XMP profile and set a faster memory clock. It might however require a very small boost to the SOC voltage (not VCore voltage) in your BIOS setup.

When buying RAM, I recommend you get 3200 CL14 or faster, in order to make sure you get Samsung B-die memory. 3200 CL16 and slower tend to be E-die or Hynix, which does not work as well with Ryzen.

Would overclocking the Infinity Fabric and raising the SOC voltage slightly, to allow use of faster memory, reduce CPU lifespan incrementally like I understand overclocking the CPU does (like in this graph)?

(I don't upgrade that often, and am hoping to squeeze as much as 10yrs out of this build. I know a lot of people upgrade more often so any effect on component longevity from overclocking isn't a problem, but that's not really my case.)

Is 2133 MHz the default, so anything over that you'd be activating the XMP profile and everything else?

Apologies for my questions (I'm still trying to read up on this stuff - don't have the knowledge that many here do). Thanks for your help as well as for pointing out about the Samsung B-die memory (which I'd read a *little* about).
 

Valantar

Golden Member
Aug 26, 2014
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@wchang99 Don't worry about the effects of overclocking on longevity unless you really go all-out on voltage. I'm writing this on a 2008 Core2Quad Q9450 (2.66GHz) currently running at 3.52GHz. I used the motherboard's built-in OC function for years, which typically raises voltage far too much, yet even that was stable. Now I'm running a custom OC, and thus have pushed the CPU 500MHz further than before. I thought it died earlier this year, but that turned out to just be a bad DIMM, and after removing it everything works just fine. As the PC is coming up on nine years old now, I would say overclocking really hasn't had any detrimental effects on it.
 
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JimmiG

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Feb 24, 2005
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Well in theory, any increase in voltage will result in a shorter life span. However, the SOC voltage increase is very tiny (+0.025V in my case), and it might not even be necessary for everyone, especially after the next BIOS update which will further improve memory stability/compatibility (coming April 11 for most boards).

Higher speed memory runs at a higher voltage, typically 1.35V instead of 1.2V, which in theory also puts more stress on the memory chips and memory controller. Since there's no JEDEC standard for such high speeds, memory advertised as 3000, 3200 etc. actually use binned, factory overclocked 2133 chips. However the practice of using factory overclocked memory is so common that even Intel and AMD officially support it (XMP was actually developed by Intel as an extension to the JEDEC standard).

So yeah, if you want 100% stock everything, you'd have to stick to 2133 MHz memory, but there would be a pretty significant performance hit and for no real benefit.
 
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wchang99

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Jul 14, 2000
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@wchang99 Don't worry about the effects of overclocking on longevity unless you really go all-out on voltage. I'm writing this on a 2008 Core2Quad Q9450 (2.66GHz) currently running at 3.52GHz. I used the motherboard's built-in OC function for years, which typically raises voltage far too much, yet even that was stable. Now I'm running a custom OC, and thus have pushed the CPU 500MHz further than before. I thought it died earlier this year, but that turned out to just be a bad DIMM, and after removing it everything works just fine. As the PC is coming up on nine years old now, I would say overclocking really hasn't had any detrimental effects on it.

Thanks Valantar. That's definitely a good testimonial. I'm kind of paranoid about overclocking (partly, in addition to component longevity, because I read it can increase risk of HDD corruption; I lost work data to a overclock-unrelated HDD crash once, and never again). But I might leave myself the option to overclock sometimes, as I get a better idea (and learn from you guys) what it's about. I'll be doing 3D rendering on the build, but I might not render for months on end, so it could be ideal to overclock when I render and set it back to stock when I don't need the speed.
 

wchang99

Member
Jul 14, 2000
107
4
81
Well in theory, any increase in voltage will result in a shorter life span. However, the SOC voltage increase is very tiny (+0.025V in my case), and it might not even be necessary for everyone, especially after the next BIOS update which will further improve memory stability/compatibility (coming April 11 for most boards).

Higher speed memory runs at a higher voltage, typically 1.35V instead of 1.2V, which in theory also puts more stress on the memory chips and memory controller. Since there's no JEDEC standard for such high speeds, memory advertised as 3000, 3200 etc. actually use binned, factory overclocked 2133 chips. However the practice of using factory overclocked memory is so common that even Intel and AMD officially support it (XMP was actually developed by Intel as an extension to the JEDEC standard).

So yeah, if you want 100% stock everything, you'd have to stick to 2133 MHz memory, but there would be a pretty significant performance hit and for no real benefit.

Thanks JimmiG. I don't have the understanding of this that you do, but I can see that the SOC voltage increase you described (and any bad effect) really does seem negligible. I'll try to keep track of what's happening with the BIOS updates.

Are you saying that ideally, when all the kinks in the platform get ironed out, there shouldn't be a need to increase SOC voltage to use faster RAM (more RAM will become compatible, and compatible RAM or RAM on the QVL should mean you shouldn't need to make adjustments such as SOC voltage)? Or is it always normal to potentially have to increase SOC voltage for faster RAM?

When you said
Higher speed memory runs at a higher voltage, typically 1.35V instead of 1.2V
do you mean SOC voltage or core voltage?

I think I need to keep learning more about how this works. But, thanks for your insights - I appreciate it.
 

guskline

Diamond Member
Apr 17, 2006
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I have the GSkill FlareX DDR4-3200 CL14 ram (2x8G sticks). Really outstanding ram. At default it runs at 2400 with present BIOS but if I enable D.O.C.P. standard it sets to 3200 speed.
 
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JimmiG

Platinum Member
Feb 24, 2005
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Thanks JimmiG. I don't have the understanding of this that you do, but I can see that the SOC voltage increase you described (and any bad effect) really does seem negligible. I'll try to keep track of what's happening with the BIOS updates.

Are you saying that ideally, when all the kinks in the platform get ironed out, there shouldn't be a need to increase SOC voltage to use faster RAM (more RAM will become compatible, and compatible RAM or RAM on the QVL should mean you shouldn't need to make adjustments such as SOC voltage)? Or is it always normal to potentially have to increase SOC voltage for faster RAM?

When you said

do you mean SOC voltage or core voltage?

I think I need to keep learning more about how this works. But, thanks for your insights - I appreciate it.

If stability with high speed RAM improves in general, then fewer people should have to bump the SOC voltage. However as stated, the increase is so tiny as to be completely negligible.

1.2V vs 1.35V was referring to the RAM sticks themselves. The DDR4 spec calls for 1.2V, but high-speed memory such as 3200 MHz etc. runs at 1.35V.
 
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wchang99

Member
Jul 14, 2000
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I have the GSkill FlareX DDR4-3200 CL14 ram (2x8G sticks). Really outstanding ram. At default it runs at 2400 with present BIOS but if I enable D.O.C.P. standard it sets to 3200 speed.

Thanks guskline. I learned that's one of the first officially Ryzen-compatible RAM kits - it's in a Paul's Hardware video . It seems one of the best options (although for me I'm probably looking at 2x8GB 3200/CL16 or 3000/CL15 because my build is a lower-budget build).
 

wchang99

Member
Jul 14, 2000
107
4
81
If stability with high speed RAM improves in general, then fewer people should have to bump the SOC voltage. However as stated, the increase is so tiny as to be completely negligible.

1.2V vs 1.35V was referring to the RAM sticks themselves. The DDR4 spec calls for 1.2V, but high-speed memory such as 3200 MHz etc. runs at 1.35V.

Thanks for all of your answers, JimmiG - definitely very helpful. I need to read up to better understand this, but you've definitely set me on the right track - I appreciate it.