[Info-vax] RX-2660 DIMM bank order

[Rich Jordan]

On Tuesday, June 18, 2019 at 1:02:05 PM UTC-5, Rich Jordan wrote:
> We have a retired 'archived' server at a customer that they would like to get running again for a while; it would be easier to get ordered historical data from it than pull it together from the extracted data dumps that were pulled before it was turned off.
> 
> It is showing memory errors on Bank 0.  A service engineer (not HP) is opening it up now.  It has been off support for several years and offline for the last year.
> 
> The service guide says to do the following when loading memory:
> 
> 1 - Install DIMMs in pairs
> 2 - Ensure DIMMs in a pair are identical
> 3 - Install DIMM pairs in order of size from largest to smallest
> 4 - Install DIMM oairs in the order shown
> 
> Order in the table is Bank 0 (A,B)
>                       Bank 1 (A,B)
>                       Bank 2 (!,B)
>                       Bank 3 (A,B)
> 
> So: does anyone know if the bank fill order is required?  Or just best for performance.  If we have a bad DIMM or DIMMs, we can remove the ones in bank 0 and slide the other banks down or just relocate Bank 3 DIMMs to bank 0.  But if we have a mainboard issue with the bank 0 slots, will the machine run with nothing in bank 0?
> 
> We are trying a cleanup with pull and re-seat of the DIMMs first.
> 
> Hoping someone knows.

Looks like we have an answer.  One of the channels on the mainboard is not happy but moving the (only) two DIMMs to the other channel has the system coming up.

So a mainboard problem.