How Speed of disk refreshing too factors into refresh time

[TinyTimothy2]

I have not seen this discussed before. How can we quantify how much the disk we write to factors in speed during a refresh?
Seems like that could be a potential bottleneck.
It is not clear if there are disks, log files that need dba attention or automated jobs to keep clean

ie
SSAS
Power BI RS

[otykier]

There are no disk writes during refresh operations, as all data processing (compression, dictionary creation, etc.) happens in memory. As such, I don’t see how disk write speed could impact refresh performance.

As a general rule, when sizing hardware for SSAS, get the fastest CPU and the fastest RAM available for your budget. That’s all that matters for SSAS tabular: https://www.sqlbi.com/blog/marco/2013/02/12/hardware-sizing-guide-for-ssas-tabular/