rp5470 DIMM order

[Timo J]

rp5470 with two memory carriers:

0a 2a 1a 3a 3b 1b 2b 0b
---- ---- ---- ---- ---- ---- ---- ----

EXT 0 1024 256 512 0 0 512 256 1024
EXT 1 512 512 512 0 0 512 512 512

STM gives following warning:

"WARNING: Current loading of DIMMs failed the distribution check. This means the memory subsystem may not operate at optimal
performance levels. To correct, refer to DIMM loading rules and re-distribute DIMMs."


http://docs.hp.com/en/A5191-96018/ mentions following rules for DIMM distribution:

* Memory must be installed in DIMM pairs.
* The capacity of DIMMs within a pair must be the same.
* Install DIMMs with the greatest capacity in the lowest slot numbers.
* Install DIMMs the following slot order: 0a/b, 1a/b, 2a/b, 3a/b, and so on.

As far as I understand, those requirements are met? So why STM warns about that?

[Torsten. · Accepted solution]

Hi,

swap the 256MB modules from ext0 to ext1, IMHO this will help.

[Joshua Scott]

Torsten is correct. You need to populate in order across the extenders, so the loading order should be:

EXT0 0a/0b
EXT1 0a/0b
EXT0 1a/1b
EXT1 1a/1b
EXT0 2a/2b
EXT1 2a/2b
EXT0 3a/3b
EXT1 3a/3b

Largest DIMMs first, as you have seen.

Josh.

[goldboy]

Mikko,
The way memory should be loaded is from the high to the low meaning, you first load the large modules and then the small ones.
as Trostan mentioned if you swap the 512 with the 256 on the first carried it should work out.

1024
512
256

[Bernhard Mueller]

Mikko,

the sequence of DIMM pairs in the slots is fine. But you have only one pair of 1GB DIMMS and one pair of 256MB DIMMS.

With that you will not be able to equally balance DIMMS across the two carriers ext0 and ext1. Consequently, you will always get this warning.

Regards,
Bernhard

[Joshua Scott]

Bernhard,

Loading the modules in the order specified by myself and Torsten will eliminate this error. I have loaded a system with 4x 2GB, 5x 1GB, & 512MB pairs (and non-even numbers of each) at the same time without any warnings.

Josh

[Timo J]

Thanks for replies. I can't change the module order right now, but please be patient; you all will get the points you earn as soon as I'll get the chance to change the order.

[Torsten.]

Hi,

once you have a downtime, consider to check the firmware and update if needed.
If you have an old version, this could be a problem too.

Sort the modules as suggested!

see the release notes of the FW:
"Previous revisions of firmware reported erroneous DIMM distribution errors when mixing 1GB DIMMs with different refresh rates. The memory distribution warning is displayed at BCH when refresh rates are mixed between extenders."

Current version is 44.12!