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Alder Lake System agent voltage and DDR5

MxPhenom 216

ASIC Engineer
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What are people running for system agent voltage on alder lake systems with ddr5.

I am building a workstation for a friend and got 64gb of ddr5 5600 and when i enable xmp, it sets it to 1.25v. Seems high? Been getting errors in OCCT large dataset during cpu stress and trying to single out of its memory or cpu related. Right now im testing with xmp off (which puts SA voltage at 0.9v) and no other memory tweaks to single out memory.
 
64gb on 2 sticks or 4?
 
Sadly some board vendors are known to tweak voltages when XMP is enabled for fastest ram spec. A too high SA voltage can be a bad thing as I discovered when I started getting silent corruption on my storage devices (fixed by lowering SA voltage).
 
it sets it to 1.25v. Seems high?

Nah that normal mate. When you start heading towards 6000Mhz the default voltage goes up to around/over 1.35v.

I've got my DDR5 5800Mhz @ 1.25v up from the default 5200Mhz. Timings I can have a look see later if your keen.
 
My 6000Mhz Corsair Dominator Platinum 36-38-38-76 stock @ 1.25V, have them currently at 36-36-36-76 @ 1.30V.
 
1.25-1.35 is often what you will see on auto. From the few ADL CPUs I had they all seem to have a negative effect above 1.35. What I mean by that is the mothebroard would fail to boot or the memory would have WHEA errors for no good reason. Lowering the voltage to say 1.25v fixed it would magically fix it.

Edit: I'm talking about systen agent just so no ones confused.
 
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64gb on 2 sticks or 4?
2 sticks so 2x32gb. Hynix ICs.

I was getting 1 error on test 10 on TM5 which based on description of that one it has to do with problem with the main timings and usually its 2nd and 3rd from the sounds of it so i relaxed them from 34 to 36, CAS still at xmp of 28. It seems good now. SA at 1.25, mem vddq 1.35, mem vdd at 1.25 and cpu vdd at 1.25 (auto was 1.21).

When i deliver it ill have him run a render on one of his projects to make sure things are okay from his workload stand point. As everything seemed good in my benchmarks and testing (Cinebench, CPU Occt, 3dmark, v-ray) Possibly relax CAS depending on how it goes.

G.skill claims that this kit will boot at xmp (which it does, but id get errors in occt memtest and tm5 with no tweaks on top of xmp) but long term stability is obviously dependent on board and cpu. Its 64gb 5600 28-34-34-89 kit @1.35vdimm
 
What is the memory controller voltage at? Defaults? Running 64gb with a Cas 28?
System Agent should be good under 6000mhz at default, I've used + 0.05000v positive offset for 6000mhz.

Topography is a down fall on a lot of boards as well. 2 slots just clock better and it really shows on DDR5 (at least for now).
As an example, I have 2 boards.

B660-I ROG Strix = 2 slots
B660-G ROG Strix = 4 slots

The B660-I will overclock my memory 5200mhz C36 series Patriot 2x8 16gb to 6400mhz, XMP enabled, timings manually set 40-40-40 the rest on auto. It trains the memory and posts right up.
The B660-G on the other hand, will overclock my memory to 6000mhz on a god day with no stability. 5900mhz is just dandy though. Good performance, I just stick with 36-36-36 xmp timings.
No additional SA voltage for the B660-I board to post 6400mhz. That was also default which was posted off the CPU side 1.20v If not a touch less. I didn't screen shot it.....

That's my little input right now. enjoy!
 
What is the memory controller voltage at? Defaults? Running 64gb with a Cas 28?
System Agent should be good under 6000mhz at default, I've used + 0.05000v positive offset for 6000mhz.

Topography is a down fall on a lot of boards as well. 2 slots just clock better and it really shows on DDR5 (at least for now).
As an example, I have 2 boards.

B660-I ROG Strix = 2 slots
B660-G ROG Strix = 4 slots

The B660-I will overclock my memory 5200mhz C36 series Patriot 2x8 16gb to 6400mhz, XMP enabled, timings manually set 40-40-40 the rest on auto. It trains the memory and posts right up.
The B660-G on the other hand, will overclock my memory to 6000mhz on a god day with no stability. 5900mhz is just dandy though. Good performance, I just stick with 36-36-36 xmp timings.
No additional SA voltage for the B660-I board to post 6400mhz. That was also default which was posted off the CPU side 1.20v If not a touch less. I didn't screen shot it.....

That's my little input right now. enjoy!
Whats the mem controller voltage typical called? I am unable to to find that one. Some boards seem to have it literally have it spelled out but doesnt seem like this MSi does. But yeah it is prob at auto. Only voltages i changed were cpu vddq, mem vddq, mem vdd, vdimm, vccsa.
 
Yeah, my Asus says straight up memory controller voltage. And I suppose some boards may not even have the option at all.
 
Yeah, my Asus says straight up memory controller voltage. And I suppose some boards may not even have the option at all.

I wonder if its CPU vddq for non asus boards? That seems to be an option talked about a lot in memory OC guides for ADL along with mem vddq and mem vdd.
 
I wonder if its CPU vddq for non asus boards? That seems to be an option talked about a lot in memory OC guides for ADL along with mem vddq and mem vdd.
Yep VddQ would be accurate. Probably stay under 1.30v, closer to 1.20v the better really.

Increase the Cas, that should give you better stability. Better than pounding voltages in my opinion.
 
Yep VddQ would be accurate. Probably stay under 1.30v, closer to 1.20v the better really.

Increase the Cas, that should give you better stability. Better than pounding voltages in my opinion.
I already have it packaged up for him to come pick it up in a bit. If he has problems ill direct him to increase CAS.

I set CPU Vddq to 1.25 yesterday.
 
OK I just checked.

B660-G in "Advanced memory voltages" the setting is "Memory Controller" voltage.

When set XMP - VDD and VDDQ should be the same voltage.
Mine is 1.20v XMP, I up that to 1.250 for 5800mhz CL36-36-36 Gear 2 / 2T CR.

I already have it packaged up for him to come pick it up in a bit. If he has problems ill direct him to increase CAS.

I set CPU Vddq to 1.25 yesterday.
Yeah, that would make his life easiest. I'd say straight to CL32 which I've tested at 5800mhz, but with increased VDD VDDQ at 1.350v.

I have not yet increased memory controller voltage. I'll let someone else fry their chip before I try it haha.
 
VDD2 is IMC (officially), VDDQ_TX is not listed by Intel specifications at all, but it is very much a memory thing. Lastly is System Agent. Adjust all 3 for higher memory frequencies and or more DIMMs.

From my notes here. SA 1.25, VDD2 1.4, TX 1.3 was used to get 6600 MT/s stable on the ASUS Z690 Hero. But it changes per MB. I have SA 1.1, VDD2 1.35, TX 1.30 for for 6600 MT/s on the Gigabyte Z690. Tachyon. MSI Unify SA 1.3, VDD2 1.35, TX 1.4 for 6600 MT/s

If I'm going for 6933 MT/s for Gigabyte its SA 1.25, VDD2 1.4, TX 1.45. The ASUS Hero can't even post that high.

Edit: If you are using 2x 32GB or 4x 16GB, I would do the following SA 1.25, VDD2 1.35, TX 1.35 and start at 4800. If it posts, go up a notch. If it doesn't raise each one by 0.05 one at a time until you find which is actually the one needed to go up. You could do the opposite and start high and work your way down. (SA 1.3, VDD2 1.4, TX 1.45). Either way will take a bit of trial and error with memory stress testing.
 
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Yeah i think i changed mem vdd to 1.25 from 1.35 that xmp tried to set due to a guide i thought read for hynix that 1.35 for vddq and 1.25 for vdd is usually good enough. But maybe it would have been better to leave at 1.35.

Shit now i want to get it out of the box again to change some of this lol


Edit:

Okay so vdd2 is on auto at 1.15v.
sa at 1 25
Mem vddq and vdd at 1.35
Cpu vdd at 1.25
Not sure about TX
 
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Yeah i think i changed mem vdd to 1.25 from 1.35 that xmp tried to set due to a guide i thought read for hynix that 1.35 for vddq and 1.25 for vdd is usually good enough. But maybe it would have been better to leave at 1.35.

Shit now i want to get it out of the box again to change some of this lol


Edit:

Okay so vdd2 is on auto at 1.15v.
sa at 1 25
Mem vddq and vdd at 1.35
Cpu vdd at 1.25
Not sure about TX
I'd just clear cmos and default the board. That is the only scenario anyone needs to promise in working order condition on sale. You didn't promise write the sticker on the memory or write a qvl.

Just sayin bro.
 
I'd just clear cmos and default the board. That is the only scenario anyone needs to promise in working order condition on sale. You didn't promise write the sticker on the memory or write a qvl.

Just sayin bro.
Thats true, but im putting a little extra into this one haha. Im his tech guy he runs a business, i get paid for this so.
 
Thats true, but im putting a little extra into this one haha. Im his tech guy he runs a business, i get paid for this so.
First rule of business, never give a promise you can't keep.

That said, pull it out and do what you gotta do to call it stable.

If there's a delay, there's a delay. That's normal business if you consider to be a perfectionist. ;)
 
Vddq_tx which on msi im assuming is just CPU_VDDQ at 1.35
Vdd2 1.25
Mem vddq auto which is 1.35
SA at 1.25.

Oh, i set CL to 32 also just for safeties.

...boots and running cinebench

At least on MSI doesnt seem like it likes when vdd2 is set much higher than cou vddq otherwise it wont post. So vddq veing qbout 0.05v+ higher is prob the way to go. Wheb i only changed vdd2 to 1.25 leaving vddq at auto which set it to like 1.15 it didnt post. Set cpu vddq to 1.35 then it post
 
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Vddq_tx which on msi im assuming is just CPU_VDDQ at 1.35
Vdd2 1.25
Mem vddq auto which is 1.35
SA at 1.25.

Oh, i set CL to 32 also just for safeties.

...boots and running cinebench

At least on MSI doesnt seem like it likes when vdd2 is set much higher than cou vddq otherwise it wont post. So vddq veing qbout 0.05v+ higher is prob the way to go. Wheb i only changed vdd2 to 1.25 leaving vddq at auto which set it to like 1.15 it didnt post. Set cpu vddq to 1.35 then it post
Correct. MSI calls TX CPU_VDDQ. Why does every vendor needs to change these names? IDK.... For mem VDD/VDDQ (DRAM Voltage), I just leave them the same. XMP profile does, so I don't see a reason to change one and not the other.

I would not go over 1.45V for the TX voltage. Even that may end not not being good for it. Lots of conflicting information.
 
Correct. MSI calls TX CPU_VDDQ. Why does every vendor needs to change these names? IDK.... For mem VDD/VDDQ (DRAM Voltage), I just leave them the same. XMP profile does, so I don't see a reason to change one and not the other.

I would not go over 1.45V for the TX voltage. Even that may end not not being good for it. Lots of conflicting information.
I think ill leave vddq tx at 1.35 and vdd2 at 1.25. Mem vddq is at auto which seems to sync it too dram voltage from xmp. This seems good for now. If he calls me about a crash or anything i at least know a bit better noe what itll need.
 
2 sticks so 2x32gb. Hynix ICs.

I was getting 1 error on test 10 on TM5 which based on description of that one it has to do with problem with the main timings and usually its 2nd and 3rd from the sounds of it so i relaxed them from 34 to 36, CAS still at xmp of 28. It seems good now. SA at 1.25, mem vddq 1.35, mem vdd at 1.25 and cpu vdd at 1.25 (auto was 1.21).

When i deliver it ill have him run a render on one of his projects to make sure things are okay from his workload stand point. As everything seemed good in my benchmarks and testing (Cinebench, CPU Occt, 3dmark, v-ray) Possibly relax CAS depending on how it goes.

G.skill claims that this kit will boot at xmp (which it does, but id get errors in occt memtest and tm5 with no tweaks on top of xmp) but long term stability is obviously dependent on board and cpu. Its 64gb 5600 28-34-34-89 kit @1.35vdimm
nice for you, I got a pair of 2*32 Gskill DDR5600 CL30 on Gigabyte Z690UD AX and i7-12700kf, it will boot at XMP but even with vccsa up to 1.35v it will have rounding errors in prime 95 within 5 min and any sort of gaming will crash it, refusing to boot again for quite a while, only going with 1.25v VCCSA and with XMP, manually tuning it down to 5200MT/s and it passes 1hour of prime 95
 
My 6000Mhz Corsair Dominator Platinum 36-38-38-76 stock @ 1.25V, have them currently at 36-36-36-76 @ 1.30V.

I just did a new build. And must admit I am not into DDR5. Its brand new for me. I did although buy a very nice kit of 2 stick .. G Skill 6000 36-36-36-96 @ 1.35. I did however some OC and they could do 6600 Mhz with improved timings. 36-36-36-72 and a lot of secondary very low. It gave almost 10% bandwidth and latency improvement. BUT it came at a cost, 1.425v. Under a stress test they get very hot but pass but im gaming and normal use totally great temps. But seeing you running 1.3v hehe... ?!! Thats very good I assume, considered mine stock was 1.35v. Was they rated like this or did you undervolt? Also what is the difference between VDD and VDDQ ram voltages?
 
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