AMD Threadripper 2990WX and ECC memory

AMD TR 2990WX supports ECC memory? I tested it and found it supports Unbuffered ECC memory but it does not recognize Registered ECC memory at all.

Summary

• Unbuffered ECC memory is recognized and it can be used as ECC memory. 
• Registered ECC memory is not recognized at all and it cannot be used. Entire memory area does not show up.

Computer configuration

• AMD TR 2990WX
• ASUS Zenith Extreme motherboard.
• Kingston KVR24E17D8/16 16GB unbuffered ECC DIMM x4, total 64GB

Checking error correction function of DRAM on Windows

Powershell command:

wmic os get caption,osarchitecture,version
wmic CPU get Name
wmic CPU get NumberOfCores,NumberOfLogicalProcessors
wmic bios get manufacturer,name,version
wmic memorychip get banklabel,manufacturer,partnumber,speed
$a = Get-WMIObject -Class "Win32_PhysicalMemoryArray"
Switch ($a.MemoryErrorCorrection) {
    0 {Write-Host "ECC Type: Reserved"}
    1 {Write-Host "ECC Type: Other"}
    2 {Write-Host "ECC Type: Unknown"}
    3 {Write-Host "ECC Type: None"}
    4 {Write-Host "ECC Type: Parity"}
    5 {Write-Host "ECC Type: Single-bit ECC"}
    6 {Write-Host "ECC Type: Multi-bit ECC"}
    7 {Write-Host "ECC Type: CRC"}
}

Result:

Caption                   OSArchitecture  Version
Microsoft Windows 10 Pro  64-bit          10.0.17763

Name
AMD Ryzen Threadripper 2990WX 32-Core Processor

NumberOfCores  NumberOfLogicalProcessors
32             64

Manufacturer              Name  Version
American Megatrends Inc.  1601  AMD - 3242016

BankLabel     Manufacturer  PartNumber        Speed
P0 CHANNEL A  Kingston      9965669-027.A00G  2666
P0 CHANNEL B  Kingston      9965669-027.A00G  2666
P0 CHANNEL C  Kingston      9965669-027.A00G  2666
P0 CHANNEL D  Kingston      9965669-027.A00G  2666

ECC Type: Multi-bit ECC

It seems ECC is working.


Note: AMD Threadripper 2990WX optimally works with 4x DDR4 2933 memory. I ordered wrong memory 😄

ECC error probability

I read somewhere, some datacenter, which operates 1000 PCs of 24/7, observes 3 to 5 ECC soft error events (1bit flipped and safely corrected) in one month. On this case, ECC memory is must have feature. 

If you have one PC which is used 8 hours a day sees one ECC error event in 50 years to 83 years of operation. 

BIOS settings of memory scrubbing

On some motherboard, a BIOS parameter change is needed to generate machine check exception logs, then ECC error correction event can be viewed by Windows event viewer. It seems my motherboard does not have this menu item. Hope it is enabled by default.

ASUS Zenith Extreme motherboard have a DRAM ECC enabled/disabled option. Also there is a bios setting to scrub: periodically read, check and correct 1bit flip errors on ECC memory area. I chose 24 hours interval scrub.

Testing memory error using Memtest86 v8.0

Passed the test.

Following data is interesting:

CacheHierarchy Size   Speed
L1 cache       96KB   93.13GB/sec
L2 cache       512KB  55.13GB/sec
L3 cache       64MB   16.24GB/sec
DRAM           64GB   16.07GB/sec

(This is DDR-2400 memory result)

About registered ECC memory and TR 2990WX

I have Registered ECC memory (16GB DDR4-2333 RDIMM x8) for another computer so I tested if it works or not. Found it is not recognized. Not just ECC part of the memory, entire memory is not recognized at all.

Conclusion

AMD TR 2990WX and Asus Zenith Extreme combination recognizes Unbuffered ECC memory. it seems ECC functionality is working.

But it does not recognize Registered ECC memory.

Be careful to choose correct memory type for your computer!