Software RAID with redundancy with varios drive sizes?

I've got multiple drives, around 7, that are various sizes. Is there any decent software RAID solution that has data redundancy?

What operating system? If Linux, mdadm is available. Otherwise, you could use onboard if the motherboard has it.

You may hit issues with running different sized/model drives. It may only be a performance loss, but it is not ideal.

I assume if you want software raid you don't care about speed? Flexraid will allow you to do parity protection with any number of parity drives and any number of data drives of any size (the exception is that each parity backup unit must be of equal or greater size than the largest data unit)

It isn't exactly "slow" in and of itself. It is just "slower" than a good hardware RAID card.

It also depends on what you are using for a controller and the bus between the drive and the system.