I've made a Raid 10 for my PC...or have I? Help!

Thanks to Ed's recommendation, I bought an LSI MegaRAID 9260-4i. It's the one I mentioned was $40 on eBay. You need to make sure it has enough ports, and supports the pci slot type your motherboard has and RAID levels you want.

EdTittel said:

Here's a 2015 thread from Tomshardware.com (disclosure: I wrote for them from 2000 through 2012 or so, still write all the time for their spin-off site, TomsITPro.com) that recommends an LSI raid controller. I've read LOTS of other good info and end-user endorsements all over the Web. I'm a little puzzled that I can't find anything newer with recommendations, though...
HTH,
--Ed--

At least i'm not the only one puzzled! Thank you.

LMiller7 said:

Using a controller has always been the preferred method of implementing RAID. Software RAID is poor mans RAID, used when you can't afford anything better. With the current availability of inexpensive RAID controllers there is little reason to use software RAID, certainly when reliability is a concern.

It just seemed easier considering I have everything I need to start, and I couldn't find any modern articles comparing and recommending raid cards. Plus I will eventually have 3 GPUs in my machine so I didn't want to take up pcie lanes.

You could always consider an external eSATA RAID enclosure. That would take some strain away from your PSU once those video cards are there. I don't trust built-in software RAID. "Never let software do hardware's job" was a mantra I still follow today.

I've figured out what step isn't working though. I'll try to explain it.

So right now I have 4 unallocated Drives, as I should: https://i.imgur.com/hwd0ujA.png

Now, if I try to setup the first mirror, everything works fine. The pool is created, two of the unallocated drives disappear, and a new one materialises, just how I would expect it to work. Like so: 2018-03-20 15-14-30 GIF | Create, Discover and Share on Gfycat

So next, would be to repeat this step. However Storage Spaces now has a different layout. Rather than be presented with my unformatted drives, I get this entirely different looking page. There's still a create pool button, but it's in a different place. Add drives just add drives to the already existing pool. The only option I think it could be is create pool. But watch, I never get asked to choose any drives: 2018-03-20 15-18-52 GIF | Create, Discover and Share on Gfycat

Being the first time I had done this I didn't notice the difference. You can see though, those 2 remaining drives stay unallocated, and a new Stripe appears. This made me think perhaps it was just recreating a storage pool from the first two drives, but if I move a few gigs of files onto Stripe1, the free space remaining goes does for Stripe1, but not for Stripe2!

So I have no idea. What I did next was then use Disk Management to stripe across the two, and that's where my two raids come from. No idea again why there is two raids created. But putting files on the Raid also doesn't seem to take up any space on either of the Stripes. It's like I have two raids10s, two raid0's, and two unallocated drives! Madness.

I was curious so did a Search for RAID 10, looks complicated and not made any easier being called RAID 1+0.
raid 10 - Google Search