Processors

[User2020]

Sorry folks about such novice question.    I have no experience with AMD processor.   And I have searched around and not getting any definite answers I was hoping for.

1.   I am looking to build a system that truly support ECC DDR4 UDIMM memory.   

2.  It will be great to have a PCIe   Gen 4 connection available.

I read somewhere saying Ryzen processor will all supports ECC memory.   But I can not find more information about it.

Some said that it is motherboard related also.    Some motherboard does not support ECC.   Or they have it disabled.

My limited understanding is that DRAM should be directly connected to the DRAM modules.    So, for my application, should I just find the motherboard that may have connected the ECC bits to the DIMM module ?    And any AMD Ryzen 3 processor will work ?  

BTW,  I thought PCIe connection is also directly connect from CPU to the PCIe connector.   And if so, why would some of the AMD motherboard which supports Ryzen and only support PCIe Gen 3 ?

I am looking for the lowest possible solution.

Thank in advance for the response.  

[pokester]

Ryzen is now on it 3rd gen but 4th iteration of processors. Many of the older boards support the newer processors. For instance a B450 will receive support for Zen3 in January and already supports the past couple generations of Ryzen processors. However when B450 came out PCE 4 did not exist so B450 only supports PCIe 3 even though it supports the 2 newer processors that have come out since it was new. So only B550 and X570 support PCE4 as they came out in the same generation as Zen2 when PCIe4 was introduced. 

Ryzen does have PCIe 4 baked into the CPU and on B550 all of it's PCIe 4 support is cpu controlled. For this reason IMHO there is no reason that the same level of PCIE 4 support could exist on older boards but AMD chose not to do this for whatever reason. X570 has additional PCIE 4 support than what the is built into the processor and is controlled by the chipset. 

AMD has pretty much always quietly supported ECC ram on their desktop CPUs as long as I can remember. However the motherboard has to support it too. So when I say quiet I mean that often that support seems to go without validation on the desktop CPUs and lacks the general official validated support you would see on threadripper or epyc.

Most often ECC is a workstation and server feature. Not often is it a desktop feature. 

[elstaci]

This 3 year old Tech article explains what @pokester  was saying: https://www.overclock3d.net/news/cpu_mainboard/amd_confirms_that_ryzen_supports_ecc_memory/1

I do know that AMD PRO Processors officially support ECC Memory but those aren't sold in Retail stores.

Need to go to your Motherboard's Specs and check under "Memory" to see if it supports ECC Memory or not. If it does it will tell you how it will support it.