Intel vs hard ware raid performance RAID 10

[ToastyBear]

I was using the motherboard IRST on RAID 0 for many many years now. Performance was excellent and near theoretical maximum. I recently decided to switch to a RAID 10 setup and performance tanked like crazy.

 

Using IRST with 4x4TB drives on RAID 0, i was able to score about 600MB/s read and 400MB/s write average

Using IRST with the same drives in RAID 10, i scored 300MB/s read and 300MB/s write average. 

 

Im far from an expert but this strikes me as odd. The write speeds make sense since each HGST drive is rated for something like 160mb/s.

But why does the read speed tank so much?

 

I was under the impression that RAID 0 gives 4x read performance minus overhead. While RAID 10 should give the same minus a bit more overhead. Was I mistaken and its actually half read speed vs RAID 0?

 

Or is motherboard RAID that garbage? I just want to confirm before I drop a LOT of money on a dedicated RAID card. Also how much money do I need to spend to see a significant improvement in performance? I heard RAID cards don't do anything unless you spend like $600. I searched a lot of forums and reviews and I mostly see people commenting "hardware RAID is better" but how much better. Would a current gen SAS RAID controller give me that 600MB/s RAID 10 read?

[Lurick]

Read and write speeds are generally going to be half with RAID 10 over RAID 0.

You've got two RAID 1's essentially (depending on the setup) so you'll get the performance of two drives instead of 4.

[ToastyBear]

1 minute ago, Lurick said:

Read and write speeds are generally going to be half with RAID 10 over RAID 0.

You've got two RAID 1's essentially (not really-ish, lol) so you'll get the performance of two drives instead of 4.

I was under the assumption that files are read from all 4 drives at the same time but obviously written at half speed. Is this not how it works? Or simply not how IRST works.

[Lurick]

Just now, ToastyBear said:

I was under the assumption that files are read from all 4 drives at the same time. Is this not how it works? Or simply not how IRST works.

Nope, they are read from two of the drives.

It's like a RAID 1, you don't read from both drives, you just write to one and then to the other (or both at the same time but the same file) and read from them the same if I remember all my different RAIDs correctly.

[Lord Nicoll]

RAID 10 is RAID 1+0, you get the safety of RAID 1 but the speed of RAID 0, With a RAID 10 array from 4 4TB drives, you should get 8TB of space and 4x reads and 2x writes however it requires a nice controller to do that, my server RAID controllers can manage that but SAS is designed for RAID and the controllers are pretty nice, I don't know about an integrated RAID controller on a normal board. Try a RAID 5 array, you'll get no write performance increase over a single drive, but 3 times the read speed and you get 12TB of space, but you'll only have 1 drive fault tolerance. 

 

[Technomancer__]

I prefer raid 5

Its Faster

You have a 1 drive redundancy but for me its enough

[Technomancer__]

Deleted

Edited August 6, 2017 by Ethocreeper

[ToastyBear]

Would something like an LSI 9361 or Adaptec 8805 be good enough? Or can i get away with something much cheaper like LSI 9300