Threadripper RAM ability

[James Scheuerman]

I'm thinking about getting a 1950X in a couple months, But I can't find the information I'm looking for.

On my last build, both CPU and motherboard said they supported dual channel memory, but I later found out only when using two of the four slots, when using all four slots, it dumbed it down to single channel due to some processor limitation

I want to get 32GB and possibly upgrade it to 64 later, but I want to ensure I get the full quad channel both the 1950X and motherboard are claiming, here's what I could find:

Motherboard Asus ROG Zenith Extreme sTR4 AMD X399:
Number of Memory Slots 8×288pin
Memory Standard
DDR4 3600(O.C.)/ 3200(O.C.)/ 2800(O.C.)/ 2666/ 2400/ 2133
* Refer to www.asus.com for the Memory QVL (Qualified Vendors Lists).
* Hyper DIMM support is subject to the physical characteristics of individual CPUs.
Maximum Memory Supported
128GB
Channel Supported
Quad Channel


CPU AMD Ryzen Threadripper 1950X:
Max Type DDR4-2666
Supports ECC Yes
Max Mem 1 TiB
Controllers 4
Channels 4
Max Bandwidth 79.47 GiB/s
Bandwidth
Single 19.87 GiB/s
Double 39.74 GiB/s
Quad 79.47 GiB/s

Thanks in advance

 

[photonboy]

First off, there are apparently different settings I don't understand that affect latency:
http://www.guru3d.com/articles-pages/amd-ryzen-threadripper-1950x-review,20.html

DDR4 bandwidth?
https://www.phoronix.com/scan.php?page=article&item=threadripper-linux-ddr4&num=4

I know that's Linux but if someone can find a good article comparing DDR4 bandwidth in Quad specifically for the 19050X then link it below... but if I understand correctly 4x3600MHz is still benefitting?

*Remember that while Quad does double bandwidth vs Dual Channel you also have 2x the cores (16 cores) so full load is almost 2x as demanding on a 16-core as an 8-core thus you need the extra bandwidth.

**So I recommend something like:
4x8GB 3200MHz CL15 DDR4

Is ECC needed? I've seen plenty of recommendations that do NOT use ECC perhaps due to cost. Unless the application is critical like a server perhaps it's not justified? (there are other error correction mechanisms and you can run MEMTEST86 too).

 

[photonboy]

Also, there are new boards and the 2nd gen TR CPU's coming soon:
https://wccftech.com/amd-ryzen-threadripper-2990x-2950x-august-launch/

That might not affect pricing much and it may not be worth the cost either though. For example, if the TR-2950X ends up 10% faster but costs $200 to $300 more is that worth it?

Not sure if the new motherboards offer anything useful. The ones that support 32-core well are probably too expensive to bother with. Not sure if STOREMI ( hybrid SSD + HDD option) is offered already for TR boards or not (it's new to X470 with regular desktop).

 

[James Scheuerman]

Hi, thanks for the info, but that doesn't really answer the question. I'm just trying to find out if the RAM will run in quad channel no matter how many DIMM slots are used, because on my current setup I found out it only supports dual channel when using two DIMM slots and when you use all four, it downgrades it to single channel only

 

[photonboy]

Hi, thanks for the info, but that doesn't really answer the question. I'm just trying to find out if the RAM will run in quad channel no matter how many DIMM slots are used, because on my current setup I found out it only supports dual channel when using two DIMM slots and when you use all four, it downgrades it to single channel only

On a Quad Channel board with eight DIMM slots you will get Quad Channel support if you use multiples of X4 memory sticks using the exact DIMM slots the motherboard manual tells you to.

So if you get 4x8GB that's good. You can later populate the rest of the slots with the same sticks for 8x8GB.

Other:
You should NOT be downgrading to Single Channel with four sticks in a Dual Channel capable board unless it has more than four DIMM slots and you didn't populate the correct slots, OR possibly if you are mixing memory sticks.

 

[James Scheuerman]

Hi, thanks for the info, but that doesn't really answer the question. I'm just trying to find out if the RAM will run in quad channel no matter how many DIMM slots are used, because on my current setup I found out it only supports dual channel when using two DIMM slots and when you use all four, it downgrades it to single channel only

On a Quad Channel board with eight DIMM slots you will get Quad Channel support if you use multiples of X4 memory sticks using the exact DIMM slots the motherboard manual tells you to.

So if you get 4x8GB that's good. You can later populate the rest of the slots with the same sticks for 8x8GB.

Other:
You should NOT be downgrading to Single Channel with four sticks in a Dual Channel capable board unless it has more than four DIMM slots and you didn't populate the correct slots, OR possibly if you are mixing memory sticks.

The downgrading to single channel is apparently some limitation of my current CPU, I found that information in some obscure forum when I couldn't get it to run at the speed it was rated for. Thanks for all the help =)