[SOLVED] 3000 mhz memory stuck at 2133 mhz

s22now

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Apr 10, 2018
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I recently finished building my first pc and I noticed that when using a single stick of my corsair 16GB (2 x 8GB) DDR4 3000 ram, I am able to run at the speed of 2933mhz.

However, when using both sticks, the speed is stuck at 2133mhz no matter what I changed in the bios. Does anyone know why and how to fix it?

single ram: View: https://imgur.com/a/8M2Kdoh

two ram: View: https://imgur.com/a/6aefAPx


Slots are A2 and B2 as shown in my mobo user guide and using the latest bios with xmp profile enabled
Spec: corsair vengeance LPX 16GB (2 x 8GB) DDR4 DRAM 3000MHz C15, ryzen 2700x, msi b450 tomahawk max
 
Solution
Ok, so if you haven't taken the CPU cooler off and the CPU out the check for bent pins yet, my question would be, why? That needs to happen, and if you plan to put it back you'll want to make sure you have fresh thermal paste and 91% isopropyl alcohol for cleaning the mating surfaces before you re-apply the paste and put it back together again.

boju

Titan
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A2 + B2 as in 2nd and 4th slot from cpu on your motherboard yeah?

attachment.php


Try manually adjusting your ram.

@2933 (1st/2nd gen Ryzen doesn't officially support 3000)

with timings;
16-16-16-16-36

Timings got from a set of Gskill 2933 CL16. Ryzen prefers even timings.

Another set of timings to try are 16-18-18-18-38

Dram Voltage to 1.35v

Dram timing configuration @ 3:03. Replace the example numbers in the video (13-14-14-14-28) with the numbers above.

Another setting to try @ 3:09 under Dram controller configuration for Cmd2T, set to 2T.

@DMAN999 Could this be related to the latest bios? Can remember something about bios versions mucking up memory speeds but not sure.
 

s22now

Commendable
Apr 10, 2018
14
0
1,510

s22now

Commendable
Apr 10, 2018
14
0
1,510
ok memory try it disabled, xmp profile disabled. I dont have the amd overclocking option in setting.
I try to manually set the dram frequency to something else, but nothing changes.
I dont know what else to try? advance dram configuration?

Again, I dont understand why single stick of ram works flawlessly, while two sticks I'm stuck at 2133mhz no matter what I changed
 

s22now

Commendable
Apr 10, 2018
14
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1,510
I don't even know what cmos battery is. I just recently built this pc. If I remember correctly profile 1 doesnt change anything either.

Could this be related to defect cpu or mobo? or somehow I might have damaged the cpu/mobo pins during installation. Does that explain why single stick of ram works at 2933mhz, but two sticks doesnt?
 

boju

Titan
Ambassador
Since you don't know what cmos battery is, ya might as well try remove it for a minute or two.

Shut the computer down and leave it sit for a bit so power drains. Or you can use case power button to discharge remaining power after the power cord has been pulled.

Locate the coin size battery on the mobo and remove it for a couple of minutes. Remember which side it goes back, + side up. This will reset bios and refresh hardware connected to the board.
 
Are there any tools to detect bent pins on cpu/mobo?
Yes, and you already have them. Your eyes. And in some cases, magnification like high powered reading glasses or a magnifying glass, if necessary, because you have not great eyes anymore like mine. LOL.

Bottom line is, this is likely one of four things.

1. Bent pins on the CPU.

2. A CPU cooler that is not evenly tightened all the way around and is causing one or more pins to "break contact" with it's contact point in the socket, or is OVERLY tightened and is shorting on something.

3. Memory that did not come together in one kit and is not playing nice together, for various reasons which are known when memory is not from one matched set.

4. Memory that is not compatible with the motherboard, in general, and has not been validated by the memory manufacturer for use on that board. Various reasons exist for why this might be including a fundamental dislike for some component used on some memory modules that do not play well with that chipset, timings or memory specific settings that are not favorable or possible on that motherboard or chipset or just plain having one DIMM that is faulty. Which is actually a fifth reason but I'm not re-typing this so there it is. LOL.

What is the EXACT model of the memory kit you are using? If you don't know, then install CPU-Z and look at the memory and SPD tabs.
 

s22now

Commendable
Apr 10, 2018
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1,510
2. A CPU cooler that is not evenly tightened all the way around and is causing one or more pins to "break contact" with it's contact point in the socket, or is OVERLY tightened and is shorting on something.

its 2700x stock cooler, it has a clip/lever and is extremely tight, nothing i can do.

What is the EXACT model of the memory kit you are using? If you don't know, then install CPU-Z and look at the memory and SPD tabs.
CMK16GX4M2B3000C15, Corsair VENGEANCE® LPX 16GB (2 x 8GB) DDR4 DRAM 3000MHz C15
From b450 tomahawk max website:
Is it compatible?
View: https://imgur.com/a/s7uWY0e
 
That kit isn't specifically listed on the Corsair memory finder for that board, BUT the same model with an R at the end, which only means "Red", is, so it should be compatible.

The problem is, I don't believe that. Not without making some BIOS changes. Try changing the "Gear down" mode in the BIOS, as these sticks have a CL15 latency and Ryzen does not like odd numbered CAS latency timings no matter what generation of Ryzen it is. You can also try manually changing the CAS (CL) latency to 16 instead of 15 in the BIOS.

None of that is a guarantee though. Sometimes it works, sometimes it doesn't. Simple fact is that Ryzen doesn't much like most Vengeance LPX sticks to begin with, even when they are even numbered timings. If we're being honest I'd recommend returning those sticks and getting a set that show as compatible from the G.Skill website. The Ripjaws and Trident Z sticks that show as compatible from the G.Skill memory configurator have a much higher rate of "working" than the Corsair LPX sticks. do on Ryzen platforms.
 
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s22now

Commendable
Apr 10, 2018
14
0
1,510
Simple fact is that Ryzen doesn't much like most Vengeance LPX sticks to begin with, even when they are even numbered timings. If we're being honest I'd recommend returning those sticks and getting a set that show as compatible from the G.Skill website.
Unfortunately, the return date has passed. So you would recommend G.Skill for ryzen 2700x? which specific model, any listed as compatible with b450 tomahawk max?

I suspect this might has something to with damaged pin on my CPU during installation. So I will be purchasing a new pair of memory for testing to rule out any dmg on cpu/mobo. If the new memory works, great. If not, then I probably have a much bigger problem