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Solved Double Data Rate memory actually running at half speed?

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TheDiagGuy

PCHF Member
Jul 28, 2019
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Hello again folks!
I finally got around to replacing my motherboard on my AMD rig (it wouldn't boot cold) and decided to just upgrade the whole setup with a Ryzen build
Here's the PCpartpicker list

The problem that I'm having involves the RAM.
Now before I get the lecture about "double data rate," I understand how that works, I'm just trying to make sure I'm not losing my mind here.
It's 2666 MHz, and it shows in the BIOS as 2666 MHz, but in Windows task manager it shows 1333 MHz.
CPU-Z shows DRAM as 1333, which would be right since it's half, but when I go to do a userbenchmark, it says 2666 MHz clocked at 1333 MHz in the RAM section.
On my Intel build that also has 2666 MHz RAM it shows 2666 MHz in the task manager.
I have tried a few different settings in the BIOS to correct this.
Tried setting XMP profile to auto and DRAM to auto. This changes it to 2133 MHz and it shows half of that in task manager as well.
Tried setting XMP profile to auto and DRAM to 2666, still shows half.
Tried setting XMP profile to 1 and DRAM to 2666, still shows half.
Tried setting XMP profile to 1 and DRAM to auto, it goes down to 2133 again and shows half.

Anyone have any insight?
 
I know you say you understand DDR, but just in case, or for the benefit of others, here is an explaination that I have always liked;

“Like the ticking of a clock, each tick represents a single hertz or cycle (the opening and closing of a transistor gate in this case).
A speed of 1Hz, for example, is one cycle per second; 2Hz is two per second; a MHz is 1,000,000 cycles per second; you get the picture.
The problem is when DDR (or double data rate) RAM came on the scene, it changed how data transfers were registered. Instead of only actuating once on the rise of each clock cycle, it could now also process an additional operation on the fall of that same clock cycle, effectively doubling the rate at which the DIMM could process data.
The figure for accurate measurement of data transfer requests then shifted from MHz to MT/s to adjust for this change, despite the fact that memory still operated at the same frequency.
However, marketing apparently didn’t get that memo, because many companies, in a bid to tout it as the next big thing, ignored the MT/s figure, instead referring it as MHz, while modern day memory quoted at 2,400MHz, for instance, only operates at half that frequency.”

APC Mag, Apr 2018, Issue 453

I'm wondering if you are just seeing programs with psuedo-smarts detecting DDR and doubling the speed for you so it looks right.
 
How many sticks of RAM do you have?
2 sticks of 8GB each. In slots A2 and B2 as the motherboard manual told me to do.
BIOS shows its in dual channel mode. Forgot to add that.

I know you say you understand DDR, but just in case, or for the benefit of others, here is an explaination that I have always liked;

“Like the ticking of a clock, each tick represents a single hertz or cycle (the opening and closing of a transistor gate in this case).
A speed of 1Hz, for example, is one cycle per second; 2Hz is two per second; a MHz is 1,000,000 cycles per second; you get the picture.
The problem is when DDR (or double data rate) RAM came on the scene, it changed how data transfers were registered. Instead of only actuating once on the rise of each clock cycle, it could now also process an additional operation on the fall of that same clock cycle, effectively doubling the rate at which the DIMM could process data.
The figure for accurate measurement of data transfer requests then shifted from MHz to MT/s to adjust for this change, despite the fact that memory still operated at the same frequency.
However, marketing apparently didn’t get that memo, because many companies, in a bid to tout it as the next big thing, ignored the MT/s figure, instead referring it as MHz, while modern day memory quoted at 2,400MHz, for instance, only operates at half that frequency.”

APC Mag, Apr 2018, Issue 453

I'm wondering if you are just seeing programs with psuedo-smarts detecting DDR and doubling the speed for you so it looks right.
I thought that also, so I fired up my Intel rig and checked the RAM frequency in the windows task manager. Both of my rigs are running 16 GB of 2666 MHz RAM.
The Intel rig has 4x4 GB and the AMD rig has 2x8 GB.
The intel rig shows 2666 MHz in task manager.
The AMD rig shows 1333 MHz in task manager.
Userbenchmark shows 2666MHz on the Intel rig.
Userbenchmark shows 2666MHz running at 1333MHz on the AMD rig.

It's because of those two instances that I believe there is something wrong with my RAM setup on my AMD rig.

Hmm... Maybe I could try swapping RAM between the two...

Any insights?
 
I'm out of ideas.
either everything is fine and it's just being shown 'wrong' or yes, the AMD machine is weird.
what about BIOS update on the AMD PC and have you checked that RAM is compatible with the mobo?
 
Yeah. Lol. I still love this forum. Been very helpful. Also: my CPU was benching bad because nearly everyone overclocks it thanks to that fancy ryzen master program. I ocd it to 3.7GHz and it was right where it should be when compared to others.

Thanks again for your help!
 
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