The (hopefully) final word on which 115x Intel CPUs actually support ECC RAM

[sfbayzfs]

Hello fellow price conscious system builders,

The 115X single Xeon C2xx platforms are hobbyist favorites, not only because they come in micro ATX, and even ITX form factors now, but because you can get started with a cheap Celeron, Pentium, or i3 with full ECC memory support, and upgrade later to a Xeon if you need to, when you have the cash, or the price falls.

Then the news of Intel not actually enabling ECC memory support on many CPU models which were supposed to support ECC undermined this comfortable entry level upgrade path idea - most if not all Ivy Bridge Celerons and Xeons actually support ECC, but almost no Pentiums and i3s do:

• Ivy Bridge Core i3s and ECC - Santa Clara, we have a problem...
• ECC check on Intel i3 processors
• (The original report on the Intel forums has gone missing)

Problem: The affected CPUs run just fine with ECC memory, but they do not actually take advantage of the ECC capabilities, so if there is an error in memory, it goes undetected, unrepaired, and unreported!

People were reporting mostly about Ivy Bridge, and eventually Haswell too, however there was almost no information on Sandy Bridge. (The general consensus was that almost no Ivy Bridge i3 or Pentiums supported ECC correctly, but Haswell was back to proper support for all 1150 CPUs.) I couple of years ago, I started collecting user reports from as many forum posts on the issue as I could find to make a list of which CPUs were and were not affected, but peoples' reports were often inaccurate due to incomplete information, and a popular python version of the ECC check program not reporting correctly, so I have recently been checking my CPU collection under more controlled conditions as i sort through my parts pile.

So far, testing on Supermicro X9SCL and X9SCM and -F variants with a Centos 7 install containing the compiled c version of the ecc check program, I have confirmed that every model of Sandy Bridge Pentium and i3 I have tested so far does support ECC correctly (I will add to this list over the next few days as i sort through more CPUs and motherboards, including my Ivy Bridge and Haswell CPUs on hand)

• i3-2130 - Yes
• i3-2120 - Yes
• i3-2120T - Yes
• Pentium G630T - Yes

I recall some more recent reports of Skylake also working correctly, but Kaby Lake disabling support again in many models, but I do not have CPUs with which to confirm those reports.

 

[dreamsin]

My i3-3220T runs also great with unbuffered ECC.

 

[sfbayzfs]

That is expected, and I have clarified the above, adding the "Problem" section - your CPU runs just fine, but since it is an affected Ivy Bridge i3, it is not actually using the ECC functions of your memory, so if there is an error, it will not actually be detected or repaired

I will be validating negative results later today with these Ivy Bridge CPUs which are affected:

• i3-3220
• i3-3240
• Pentium G2030

 

[dreamsin]

Oh, that is interesting. The Gen 8 Microserver I have it in, also comes with an i3-3240 from the factory, which kind of implies ECC would work.