RAID 1+0 stipe size?

General Discussion
1

I’m building a new rig have some drives I’m building into a RAID 0+1 array.

Short question up front:
What is the best STRIP size for the array?
64kb or 2mb?

Long story:
When I migrated from a HDD to SSD, I noticed an improvement to the game loading between levels. Now that I have the opportunity to build a RAID array of four drives, I’m curious as to what STRIP size in KB will help load levels faster.
I mean, I’ve gone to the extent of finding the best RAM timings for my build, but my knowledge of RAID building is limited.

Any help is appreciated.

2

If you’re using the RAID array primarily for gaming, you aren’t going to notice much of a difference between the defaults and 2 MB for the stripe size when it comes to SSDs. If you are intending to do a lot of large sequential reads (i.e. DVD rips, etc.) then 2 MB is ideal. Be aware that a lot of hardware RAID cards cap at 1 MB to limit the impact on I/O.

If you have a modern system though, you’re going to find that you’ll get better performance from a single NVMe drive than striped regular SSDs. In fact, you’ll pay more for a regular SSD RAID than you would for the same size NVMe drive in most cases.

3

Wow, that’s some pretty solid advice.
Good point about the NVMe (which my current build lacks).

I greatly appreciate your input and will certainly be thinking about this with my next build in mind.

4

I would have to second the info here with NVMe SSDs over RAID SSD configs.

I have setup several SSD RAIDs in the past, back when NVMe wasn’t a thing yet.

As for stripe size, defaults usually work for most setups. The only time you want large stripes is when dealing with large size files.

As an example, I had a customer recently request that I send them a copy of Works 9. (yes, really).

It had so many tiny files, that it was better to format the USB stick with small block sizes. Its pretty bad when a less than 700MB install would occupy over 8GB with modern formatting (which usually uses a larger block size) due to the the amount of tiny files that Works install has with its art folder. Talk about file overhead.

But that relates with setting up stripes on RAID configs. Stripes with smaller blocks have a bit better performance but a lot better space use with smaller files, and work a bit harder to deal with large files. Whereas larger blocks help larger files, but slow down considerably more with small files and can waste overall space.

The bare nuts and bolts of it:

If your block size is say 16k, and you are writing files that are less than 1k, every file still occupies at least 16k of block space. Even if its only 1k in size. And a file that’s say 20k in size will take up 32k of space. And so on. So the bigger the block, the more wasted space with regards to small files.

But the larger the file, the less it wastes, and the write time goes down. lol

Fun stuff.

I should clarify a small difference between RAID blocks and formatted drive blocks.

With RAID the Stripe block size affects how the RAID controller interacts with the drive directly, not how the files are stored on it.

You could actually format a RAID drive with a different block size than the RAID stripe block size, but its not recommended. My advice would be to use the defaults in both cases. Less likely to have an issue and it works fine.