Question Memory Rated @ 3600 shuts off PC when set to advertised speed of 3600 ?

May 11, 2021
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Hey all

Ok, so I have two RAM modules 8GB each on my B550 motherboard with an AMD Ryzen 5950x. I am avoiding to mention brand names but you can be certain they are a very well known brand.

The BIOS detects them and sets them @ 2133MHz which I found odd as I really want to run them at 3600MHz.

So all I do is get to the memory OC section of the BIOS and set the speed from Auto (2133) to 3600MHz.

Save and Exit, PC reboots, after 2-3 seconds boom it turns off (literally) and then it starts again and again after 2-3 seconds it turns off again and it starts again and again turns off, the 4th time starts up properly, I enter the BIOS and I can see the memory running at 3600MHz.

What is happening here? I set the speed down to 3200MHz (from 3600MHz), Save and Exit and PC starts normally, everything is super stable.

Weird, so I set it again to 3600 and boom same thing, PC turns off, starts again, turns off, starts again and when it finally starts up normally, I set it down to 3200MHz again and it's stable.

In the BIOS, I did not change any XMP settings, I simply put the clock speed up while the XMP is set to Auto. However, I have noticed, when I click XMP, there is profile 1 with the xx-xx-xx-xx and then next to it there is 3600Mhz. That's not what I selected the first few times, instead I merely changed the clock speed to 3600MHz without changing the XMP.

My question, I don't like those successive turn on/off/on events about 2-4 seconds apart from each other. Could have I unwittingly damaged something? My system is working fine now @ 3200 but I really want to have that 3600, that's why I paid extra. but I am scared to set the auto-detected XMP profile (Profile 1) in case the PC enters that unstable mode again.

I know that if it fails to start, I can reset the BIOS but my concern is unwittingly damaging something because of the successive on/off events about 2-4 seconds apart (in case it happens again).
 
Last edited:

bfollett

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Mar 14, 2005
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From my understanding Memory training occurs in the bios when new memory or new memory timings are input and the bios is trying to set up for those timings. Multiple reboots can occur when the memory is first "trained". If after the 4th reboot you saw 3600. You should have just left it alone unless subsequent power ons were also continuing to do the reboots. Once the system had figured out how to operate at the 3600 it should continue at that speed on first boots.
 
May 11, 2021
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Ok, sorry for late reply, different time zone, the memory is a Corsair 16GB - 2x8GB = CMT16GX4M2C3600C18 Dominator Platinum.

Motherboard is an AsRock B550 Taichi (very fast POST time even with CSM enabled, very happy with it)

In the BIOS/EFI settings, Load XMP Setting is set to Auto
DRAM Frequency
is set to 3200 (currently)

When set like that, system works fine.

Then I change DRAM Frequency to 3600 - only DRAM frequency, nothing else, XMP stays set to Auto (and this way it is set to the advertised speed) and then what I described in my original post starts to happen but when I say the system turns off an on, I mean that literally, so it not a soft reset, it is a cold boot, the power LED on the case turns off for 2-3 seconds and then the PC turns on again and again after 2-3 seconds turns off again and again in turns on, it happens about 4-5 times before it becomes stable. So I can't get it to run @ 3600 stable by simply changing the clock speed.

However later on I found out that, regardless which frequency I have selected, 2133 or 3200 or whatever, the "Load XMP Setting" has 1 entry called "XMP 2.0 Profile 1: DDR4-3600 18-19-19-39 1.35V"

I have not selected that to see what happens / what will happen. I'd say selecting that will make a difference than simply changing the frequency only because right now, when XMP is set to Auto, the DRAM voltage is set to 1.200V and as you can see the Profile 1 that's been generated by the system, it states 1.35V.

About memory training, thanks for that hint, it does sound about right, I just searched around and a lot of people do mention it, there are even some YT videos but my case is a bit more severe I guess as it involves powering down the system completely (power LED turns off, fans stop spinning and then it turns on / starts again) - a bit scary knowing it's a brand new system I only just beautifully built, very happy with it, nice and clean build and quiet too.
 
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Karadjgne

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Select XMP. From the sounds of it, you manually set the clock speed to 3600, except the voltages and timings of 2133 will not support such. 2133MHz is default for DDR4, anything above cpu memory controller defaults is considered (OC), so that definitely includes your ram. XMP sets default voltages and timings for whatever profile you select, which in your case might only be a choice of #1 3600MHz.
 

Jason H.

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Hey all

Ok, so I have two RAM modules 8GB each on my B550 motherboard with an AMD Ryzen 5950x. I am avoiding to mention brand names but you can be certain they are a very well known brand.

The BIOS detects them and sets them @ 2133MHz which I found odd as I really want to run them at 3600MHz.

So all I do is get to the memory OC section of the BIOS and set the speed from Auto (2133) to 3600MHz.

Save and Exit, PC reboots, after 2-3 seconds boom it turns off (literally) and then it starts again and again after 2-3 seconds it turns off again and it starts again and again turns off, the 4th time starts up properly, I enter the BIOS and I can see the memory running at 3600MHz.

What is happening here? I set the speed down to 3200MHz (from 3600MHz), Save and Exit and PC starts normally, everything is super stable.

Weird, so I set it again to 3600 and boom same thing, PC turns off, starts again, turns off, starts again and when it finally starts up normally, I set it down to 3200MHz again and it's stable.

In the BIOS, I did not change any XMP settings, I simply put the clock speed up while the XMP is set to Auto. However, I have noticed, when I click XMP, there is profile 1 with the xx-xx-xx-xx and then next to it there is 3600Mhz. That's not what I selected the first few times, instead I merely changed the clock speed to 3600MHz without changing the XMP.

My question, I don't like those successive turn on/off/on events about 2-4 seconds apart from each other. Could have I unwittingly damaged something? My system is working fine now @ 3200 but I really want to have that 3600, that's why I paid extra. but I am scared to set the auto-detected XMP profile (Profile 1) in case the PC enters that unstable mode again.

I know that if it fails to start, I can reset the BIOS but my concern is unwittingly damaging something because of the successive on/off events about 2-4 seconds apart (in case it happens again).
You need to enable the XMP. Your only changing the speed. The timings and voltages must also be changed, which xmp does. Or if you can, set them manually yourself to match the XMP values.

Also, regardless XMP works or not, I know the advertised speed is 3600mhz, but its not always a guarantee to work that high and they even tell you this in the fine print.

This is the same way most of the time you can use 2 different ram chips of the same brand, with the same speed and timings and 1 of them each being from different sets, but its not ever guaranteed to work and thats why they make sets.

They say "up to 3600mhz" they never guarantee it.
 

Karadjgne

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They say "up to 3600mhz" they never guarantee it.
Oh no. It's guaranteed. If they say it's rated at 3600MHz, it's guaranteed to hit that and be stable. What's not guaranteed is that it will do it on any particular setup. It may easily hit that number or better on my pc, and their test bench, and half a dozen other ppls pc's, but there's no guarantee it'll happen on yours.

That's like motherboard QVL, they might have tested specific ram models at specific speeds on a specific motherboard, but at the end of the day, there's no absolute guarantee that the same model ram on the same model motherboard as tested, will work for you. It's 99.99% sure it will, but that's still not a guarantee.

There are very few actual guarantees on anything, because everything has a failure rate, even if it's 0.00001%.
 
May 11, 2021
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Thanks all, I think I figured what caused the multiple random shut downs (thanks to all of you) and it turns out I counted correctly, I said the system turned on / off (power LED turning off, fans / hard disk stops spinning etc) about 3-4 times.

So I went through the BIOS options just to see what's available and I found a setting called: DRAM Timing Configuration.

In it, I can do custom timings but further down the page there is a setting called: "Fail Count" and when clicked, the Help Text on the right hand side says: "The number of training failure/retries required before boot from recovery mode." and that number is set to 3 :) which matches my observations when my system turned Off and On randomly after I set the frequency to 3600.

It must have been failing to boot the first, second and third time and then it loaded recovery settings and it booted the 4th time. This is really awesome, so the BIOS/EFI is coded in such a way that it knows when the system does not boot properly and when so it loads recovery settings - ones that work. What a nice feature to have.

So I set this setting from 3 to 1 so if I mess up again, it will (well that's my expectation at least) only turn Off and On once rather than 3 times. I am happy with that.

About the listed XMP profile, that will probably work but I haven't tested it yet (still collecting courage LOL) but I am just happy that the system does work as configured / designed - 3 attempts to POST, and if no success then it loaded recovery settings. I hope other brands have this nice fail safe feature too.
 

Jason H.

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Oh no. It's guaranteed. If they say it's rated at 3600MHz, it's guaranteed to hit that and be stable. What's not guaranteed is that it will do it on any particular setup. It may easily hit that number or better on my pc, and their test bench, and half a dozen other ppls pc's, but there's no guarantee it'll happen on yours.

That's like motherboard QVL, they might have tested specific ram models at specific speeds on a specific motherboard, but at the end of the day, there's no absolute guarantee that the same model ram on the same model motherboard as tested, will work for you. It's 99.99% sure it will, but that's still not a guarantee.

There are very few actual guarantees on anything, because everything has a failure rate, even if it's 0.00001%.
Im sorry I should have specified that better. Sometimes I leave critical information out while just trying to keep things simple for the op.

Thank you for correcting me!
 
May 11, 2021
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Just for the record, I selected the XMP profile but it didn't work, my PC shut down again (twice) in succession (3-4 seconds apart) while trying to POST and once it POSTed, I entered the BIOS/EFI and I saw the memory reported frequency had been set to 2133 but in the OC menu, the XMP profile of 3600 was still selected but obviously it wasn't running @ 3600 after it POSTed hence for POSTing because the status showed 2133. (despite fail count being set to 1 - so not sure what's up with that, I will set it to 0, it should have power cycled only once, not twice).

Anyway, turned out, I am not the only one struggling to hit that 3.6GHz point, there is post on Reddit and the OP also has a B550 Taichi motherboard and same RAM chip as mine but 32GB instead with a Ryzen 5900x but he managed to get it going eventually with some specific settings:
reddit link


I decided to leave my RAM running @ 3200MHz as it is super stable. I am reading around and I see a number of people have issues going above 3200 so it's not just me as per that link I posted (and some other articles I have read).

Here is something else (off topic), a few days ago, I completely ran out of RAM, and I am talking about 0MB left, my system froze completely, a picture frame, mouse won't move, no response from keyboard and when it happened (a few times), I literally saw the memory (as reported by free -h) dropping down to < 150MB when it came down from 15GB. It was weird something like that happening on Linux.

What was I doing to cause this? Compiling LLVM and set the job count to 32 (all logical CPUs / threads). Little did I know when doing stuff like this I need heaps of RAM about 2GB per thread so my newly built 5950x came to a crawl, it felt like using a Pentium 100 or a Cyrix chip in the 90s :( So I am getting additional 32GB of RAM, hopefully that will be enough and I won't need 64GB. The new RAM I am getting is again Corsair but the low profile one, Corsair Vengeance LPX 32GB so I will mix it up a bit still "rated" at 3600.

My current DIMMs are too tall, I have a Noctua NH-D15 with two fans, I can't use the second fan as it hits the memory chip and when I lift the fan a bit, it hits the side of the case so I removed that fan and the cooler is running with one fan. Amazingly, the CPU runs nice and cool even during compilation and with one fan on the heat sink. I looked in my case, it looks like I have enough space to work under the heat sink to install the additional DIMMs, so judging by the looks of it, it will be fine hence for getting this low profile DIMM and other people say the same thing - it's perfect for large heat sinks.
 
Last edited:

dorsai

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If you're overclocking your CPU turn off the overclock.
Reset all memory timings to Auto.
Manually set 1.375v for the memory and reboot.
Reboot again and jump in the BIOS to verify 1.375v is still set...if it is, go ahead and select the XMP profile and reboot.
You should be at the XMP profile rated speed.

If it won't run at the XMP profile with 1.375v you should RMA the ram for replacement.
 
Just for the record, I selected the XMP profile but it didn't work, my PC shut down again (twice) in succession (3-4 seconds apart) while trying to POST and once it POSTed, I entered the BIOS/EFI and I saw the memory reported frequency had been set to 2133 but in the OC menu, the XMP profile of 3600 was still selected but obviously it wasn't running @ 3600 after it POSTed hence for POSTing because the status showed 2133. (despite fail count being set to 1 - so not sure what's up with that, I will set it to 0, it should have power cycled only once, not twice).

Anyway, turned out, I am not the only one struggling to hit that 3.6GHz point, there is post on Reddit and the OP also has a B550 Taichi motherboard and same RAM chip as mine but 32GB instead with a Ryzen 5900x but he managed to get it going eventually with some specific settings:
reddit link


I decided to leave my RAM running @ 3200MHz as it is super stable. I am reading around and I see a number of people have issues going above 3200 so it's not just me as per that link I posted (and some other articles I have read).

Here is something else (off topic), a few days ago, I completely ran out of RAM, and I am talking about 0MB left, my system froze completely, a picture frame, mouse won't move, no response from keyboard and when it happened (a few times), I literally saw the memory (as reported by free -h) dropping down to < 150MB when it came down from 15GB. It was weird something like that happening on Linux.

What was I doing to cause this? Compiling LLVM and set the job count to 32 (all logical CPUs / threads). Little did I know when doing stuff like this I need heaps of RAM about 2GB per thread so my newly built 5950x came to a crawl, it felt like using a Pentium 100 or a Cyrix chip in the 90s :( So I am getting additional 32GB of RAM, hopefully that will be enough and I won't need 64GB. The new RAM I am getting is again Corsair but the low profile one, Corsair Vengeance LPX 32GB so I will mix it up a bit still "rated" at 3600.

My current DIMMs are too tall, I have a Noctua NH-D15 with two fans, I can't use the second fan as it hits the memory chip and when I lift the fan a bit, it hits the side of the case so I removed that fan and the cooler is running with one fan. Amazingly, the CPU runs nice and cool even during compilation and with one fan on the heat sink. I looked in my case, it looks like I have enough space to work under the heat sink to install the additional DIMMs, so judging by the looks of it, it will be fine hence for getting this low profile DIMM and other people say the same thing - it's perfect for large heat sinks.
Three things affect memory overclocking - the CPU (memory controller), the motherboard and of course the DRAM modules. In you case the AMD Ryzen 5950x the system memory speed is "up to 3200". See System Memory at https://www.amd.com/en/products/cpu/amd-ryzen-9-5950x

Although 3600 is advertised for the memory modules your CPU memory controller does not support that speed regardless of what the motherboard BIOS or the DRAM modules say.
 

Karadjgne

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In you case the AMD Ryzen 5950x the system memory speed is "up to 3200".
That's the speed of the memory controller. Has nothing to do with speeds of the ram. You can pair a 5950x with 5.0GHz ram.

The chipset speeds to maintain a 1:1 ratio with Zen3 and infinity fabric is (according to AMD) supposed to be 4000MHz ram. But nobody (including professionals) has really been able to get that stable. Instead, for a 5 series cpu, 3800MHz and an fclock of 1900 is optimal.

With Zen2, that ceiling was 3733MHz, so 3600/1800 was optimal. With Zen/Zen+ the ceiling was 3466MHz, so 3200/1600 was optimal.

Memory controller default speeds for Zen was 2133MHz. Zen+ 2400MHz, Zen2 2666MHz, and Zen3 is 3200MHz.

Meaning anything faster than that is considered (OC) when it comes to ram.

XMP is a default set of values. It's supposed to work as is, but because it's (OC), there's no guarantee for any particular setup. Voltages might need adjusting, timings, memory controller voltages etc. It's all part of the silicon lottery, some ram sticks just don't mesh well with a particular motherboard / cpu.

You might try Dram Calculator from guru3d.com (you'll also want to get Typhoon Burner and follow the setup instructions exactly). Try that in safe settings, but leave the XMP main timing values alone as is, only change the secondary timing settings. Save that setup as a profile in bios. Shouldn't have any issues hitting 3600 doing it manually, although bumping dram voltage to 1.37v can help as can a slight bump to memory controller voltages.
 

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