Curious how RAID0 interacts with SATA

[Lovestar]

Hi guys, I'm currently designing a build for a completely new system which will be used for both gaming and recording/video editing/creative stuff.

Because I'll be doing video work, I want to put some of the 7200 RPM drives in a RAID0 array. I'm curious how SATA bandwidth limits interact with RAID arrays.

Here's some stuff I've learned:

• ■ A single 7200 RPM will max out (under ideal conditions) around 150 MB/s transfer rate.
  ■ If you RAID0 that drive with another one, then both of them together will have (on paper) about 300 MB/s transfer rate.
  ■ SATA 3.0 Gb/s maxes out (on paper) at a transfer of about 380 MB/s.

Does this mean that if you put 3 RAID0 platter drives together, making (ideally) 450 MB/s transfer rate, they would saturate / be throttled by a SATA 3.0 Gb/s connection?

Or is it actually not throttled, because each individual SATA 3.0 Gb/s connection is transferring each individual drive's 150 MB/s, so they still sum up to 450 MB/s together, even though SATA 3.0 Gb/s can't transfer that fast from any one individual connection?

This is one thing I haven't been able to figure out about how RAID works, despite a lot of Googling and reading about it. I appreciate if anyone can clarify it for me. =)

 

[oczdude8]

ur second opinion is correct. The sata transfer rates add up.

I use ssds on a sata 3.0 port (250mbs cap, supposed to be ~300) and in raid 0 I get just under 500mb read/write, which is expected since my SSDS are fully bottlenecked at 250mb/s and theres 2 of them

also RAID doesn't scale exactly. If you have 2 drives, you will get around 200-300 range

also using 3 drives using a onboard raid controller may not be the best idea. You may not get the performance you calculated on paper, and it is prone to greater errors

 

[Lovestar]

Thanks. You also gave me some more stuff to research. =)