Comment Re:data || GTFO (Score 1) 94
If you go old enough, you have to take into account that memory bandwidth was terrible.
On a Pentium 1, I believe RAM can do somewhere around 100MB/s. And sure, it gets better later, but still. If you consider that a serious RAID-5 for instance, you're reading at a minimum 3 drives, and computing parity, then yes, you can easily take most of your memory's bandwidth just on that. It makes a lot of sense then to offload stuff to a RAID card.
These days hard disks are laughably slow compared to the rest of the computer, but it didn't use to be quite like that. A high end SCSI drive of the era might do maybe 20 MB/s, which is a good fraction of the system RAM's capability. Put just 3 there and it's starting to get tricky.
Also, we have the benefit that some slowness stopped to matter. If you're RAID5-ing 3 x 8GB/s NVMes and not getting the ideal performance out of it there's lots of cases where that doesn't matter because you don't have a workload capable of doing anything with what even a single drive is capable of providing anyway.