Ryzen 2xxx single rank vs dual rank, ECC vs non-ECC

[mfeller2]

When the first Ryzens came out, there were several articles detailing how the default max memory speed changed depending on rank and ECC support. Best support was for single-rank, no ECC.

For example:
http://www.legitreviews.com/amd-ryzen-single-rank-versus-dual-rank-ddr4-memory-performance_192960

I have so far not been able to find any similar detail for the Ryzen 2xxx generation. Is anyone aware of any similar articles, etc.?

Background: I am putting together a PC that I will use for some simulation activity, and for this reason, I focused on having ECC. I will also do some occasional gaming, and I am looking at the RAM specs, and the penalty of going with ECC, and am re-thinking this a bit. CL19! Dual-rank! Limited to DDR4-2666!

Thanks!

 

[Markfw]

Well, someone here posted that ecc was fully supported by Ryzen, but not tested (or something like that). Yes, 2666 was the fastest ECC I could find, and yes, it will slow it down. If they made faster ECC, Ryzen seems to work to 3466 (in all my boxes, except one at 3200.). I would love to do tests if some memory mfg would give me 16 gig of 2666 ECC.

 

[mfeller2]

Part of my concern is that with the previous Ryzen, even if you bought a faster speed RAM, it would want to run slower if it was dual-rank, for example. Of course, you could then overclock to bump it back up.

I am already giving up a bit on latency, and being limited to 2666 just from what's available with ECC. If ECC + dual rank causes Ryzen 2xxx to want to drop that 2666 down to something lower, this is what I am looking for. How low does it go?

 

[fleshconsumed]

In my experience ECC ram works with Ryzen at its rated speeds. I did not experience any speed drops when I filled out all 4 slots with 4 sticks of dual ranked ECC ram.

I had:
- AsRock X370 Professional Gaming (top tier) with 1800X
- Asus X470 Prime Pro (mid tier) with 2700X

Both configurations ran 4 sticks of Kingston 2400 CL17 16GB dual-ranked ECC ram for a total of 64GB at its rated speed of 2400. Granted, my sample size is only 2 motherboards, but I had zero problems maxing out RAM with dual-ranked sticks running at their rated speeds.

 

[BigDH01]

I have a 2700x in a Gigabyte Aorus Gaming 5 (x470) with GSkill 3200CL15 (2x16 GB, dual rank) which is Samsung B die. It will *not* run at rated speeds. Best I can do is 3000 but I can lower CAS to 14. Anything over 3000 just results in random blue screens.

 

[ZGR]

Single rank overclocks better on either Intel or AMD.

 

[wahdangun]

yu can overclock ECC memory in Ryzen, i have managed OC'd Ram to 3000 MT\s on Asrock A320

 

[richaron]

yu can overclock ECC memory in Ryzen, i have managed OC'd Ram to 3000 MT\s on Asrock A320

This, though I'm not sure about the 1xxx vs 2xxx situation. But I'm pretty sure the info in the link OP posted is outdated even for the old platform.

ATM I'm running 64GB (4 x 16GB) dual ranked ECC on a 1700 system where the board/CPU claim 2400MT/s max (and it's def not on the QVL). The RAM's rated for 2400 CL17 @ 1.2V but appears to run 3000 @ 1.35V with the same timings comfortably. I'm sure I could push the speed up still (or voltage down) but I wanted to keep comfortably stable, although once this system no longer games and runs more mission critical stuff I'd probably drop the speed a little further. I can't imagine the 2xxx chips are much worse though IDK

 

[JoeRambo]

I am not familiar with Ryzen memory situation, but on Intel, at least on Asus motherboards with T-Topology memory layout it is better to run with all 4 slots filled. From Asus claims and personal experience such setup can achieve higher mem clocks and also be a fraction of % faster on same speed/timing settings due to increased concurrency in memory requests.

 

[kjboughton]

ECC memory is not inherently slower as all the programmed timings are irrespective of memory technology employed. Generally ECC memory timings cannot be significantly altered using platforms for which it operates (typically as the motherboards used are not designed for overclocking). Otherwise, ECC memory can be forced to run at higher frequencies similar to what non-registered memory is capable. Certainly not the gold star winners but respectable nonetheless.

The confusion comes in as a function of memory loading. We all understand that increasing amounts of memory result in proportional increases in bank capacitance, right? (I kid.) This means higher memory loading directly results in lower maximum memory frequency. This can be achieved as such, or in the relaxing of certain key memory timings.

Furthermore, the only memory timing which relates directly to rank count/usage is Command Rate (CR) which usually must be relaxed from 1T to 2T (or higher although rarely seen these days) in order to run higher density memory or simply more modules in parallel.

If you care about long term stability you need ECC memory. Them's the breaks.

FCG

 

[fleshconsumed]

This, though I'm not sure about the 1xxx vs 2xxx situation. But I'm pretty sure the info in the link OP posted is outdated even for the old platform.

ATM I'm running 64GB (4 x 16GB) dual ranked ECC on a 1700 system where the board/CPU claim 2400MT/s max (and it's def not on the QVL). The RAM's rated for 2400 CL17 @ 1.2V but appears to run 3000 @ 1.35V with the same timings comfortably. I'm sure I could push the speed up still (or voltage down) but I wanted to keep comfortably stable, although once this system no longer games and runs more mission critical stuff I'd probably drop the speed a little further. I can't imagine the 2xxx chips are much worse though IDK

Curious, are you using Kingston or Crucial 16GB ECC sticks?

 

[richaron]

Curious, are you using Kingston or Crucial 16GB ECC sticks?

I'm using this Crucial kit (CT4K16G4WFD824A). Thankfully I didn't pay quite that much

Motherboard is an ASUS X370-F with latest bios (#4012, AGESA 1.0.0.2a).

Edit: RAM stick part number: mta18ASF2G72AZ-2G3B1

 

[Rancor]

Not ECC specific but Techreport mentioned the following Re memory controller.

All second-generation Ryzen CPUs enjoy a more robust memory controller than first-generation Ryzens, too. As it does with Raven Ridge desktop parts, AMD rates second-gen Ryzens for DDR4-2933 support from single-rank, two-DIMM memory configurations (although only from motherboards with six PCB layers, oddly enough). Using more DIMMs or dual-rank memory will cause stock memory speeds to drop off, just as with first-generation Ryzen parts. Even with that in mind, our hands-on testing with AMD's demo X470 systems at an event in New York suggested that overclocked memory speeds in the range of 3600 MT/s with two DIMMs could be achievable with some care. That's a major improvement over first-gen Ryzens, where speeds greater than 3200 MT/s proved difficult to reliably achieve without exacting choices of memory kits and motherboards.

I imagine the Ryzen 2000 memory controller acts similarly to the original series (common memory configurations), just with improved frequencies.