DL360 Gen10 RAM upgrade query, two part numbers: 840758-091 vs 815100-B21

[T_1_6]

Hope someone can help! Simple enough query.
We want to upgrade RAM on our servers, Oneview reports 840758-091 being installed in all our servers. However, our original server builds had 815100-B21 on the purchase order.

I would definitely like the identical part number to show up in Oneview in all the RAM slots, what is the meaning of two different part numbers for the same product?

Is it that the B21 is a commercial front number with different variations/manufacturer/batches of RAM behind it, and that the 840758-091 is actually specific and identical RAM and if I order this P/N I get 100% that coming up in Oneview?

Many thanks!

[KevinSpringPM]

One number is used for purchase orders and the other is used for factory assembly/technical things like OneView. If you order the same B21 SKU then you should get the same SKU showing up in OneView. This usually happens when we have one physical part that has multiple sellable SKUs, not the other way around like you'd guessed.