Whats the difference between an HBA card vs a RAID Card?

[ZachTheDoggo]

I'm trying to figure out what the difference between an HBA card and an RAID card? The only difference that I found is that with HBAs you can connect multiple drives but there isn't an onboard raid controller on the PCIE card, while with the RAID card you can do the same thing but you're limited in terms of external or internal SAS ports. 

Am I wrong or correct? I'm trying to build a server for myself and i'm confused about those 2 options.

[RONOTHAN##]

HBAs give the OS direct control over the drives letting you use software RAID (generally more reliable) while Raid cards handle all the RAID calculations on board and appear to the OS as if you only have a single drive. 

 

Generally you want to be using an HBA if possible so you can use software RAID, or find a RAID controller that you can flash into IT mode and use it as an HBA. 

[Windows7ge]

You're pretty close. An HBA is just a controller that provides an expansion of SAS/SATA ports. What manages the drives is up to the OS.

A RAID Controller is like an HBA but has the onboard functionality to create a array which is then presented to the OS as a singular drive.

 

To contradict RONOTHAN## a little due to what sounds like a bias...there are pros and cons to each solution. The industry as a whole is starting to migrate to predominately OS based RAID solutions. Windows has Storage Spaces, Linux & UNIX have various File Systems that provide RAID features. If you want to follow industry trends you can use OS based RAID. It's a perfectly fine option.

 

On the oppose side of the fence. Depending on your hardware you can use a hardware RAID controller. These have a theoretical limit as to how many drives you can connect (4, 8, 16, 24) but this is usually circumvented with what are called SAS expanders which in turn can proved more ports for more disks. The controller is designed to do one job really well which can alleviate CPU load. OS based RAID is CPU reliant. Depending on the complexity of the array you can be CPU bottle-necked but this usually isn't a problem you'll run into with a home server. Not nearly enough disks. Additionally if your RAID card fails migrating an array to another RAID card isn't a plug'n'play task. There's also issues with data corruption and what can be lack of error checking which is why you don't want to cheap-out if you use a hardware RAID card.

 

There's many other examples but it's not as though either solutions is superior really. Both have their pros and cons. Which is better is dependent on your use case and other hardware. Choice of OS. Etc...

[LIGISTX]

6 hours ago, ZachTheDoggo said:

I'm trying to figure out what the difference between an HBA card and an RAID card? The only difference that I found is that with HBAs you can connect multiple drives but there isn't an onboard raid controller on the PCIE card, while with the RAID card you can do the same thing but you're limited in terms of external or internal SAS ports. 

Am I wrong or correct? I'm trying to build a server for myself and i'm confused about those 2 options.

If your planning to use truenas or unraid, you want an HBA. 
 

Some RAID cards (my Dell H310 for example) can be flashed to IT mode which turns them into an HBA.