PCIE 3.0 SATA III Controller vs Onboard SCU SATA 2.0

[CowboyRedBeard]

I'm a little out of my depth here... but since migrating to the new server I've started looking at drive speeds more closely. Especially since that's now more of a problem for me than basically all the other stuff.

 

What I've got:
SuperMicro X9DRi-LN4F+
SPECS

With dual E5-2690 v2 @ 3.00GHz

128GB of DDR3

All my drives are SATA III (mostly 5k RPM)

 

So... I'm wondering if I get a PCIE (3.0 on this board) SATA III controller if that'd be faster disk access to my drives than the onboard SATA II or SCU SATA II that I've got today. This board only has 2 SATA III ports so I'm presently using them for my SSD Cache drives.

 

I mean, SATA II is 3.0 GPS and and PCIE 3.0 is roughly 7.88 Gbps right? So in theory it'd be faster unless ALL the drives on that card were running at the same time?

 

Or am I way off here?

Edited June 17, 2019 by CowboyRedBeard

[JorgeB]

SATA2 is plenty enough for current spinners, just not for SSDs.

[CowboyRedBeard]

Do you think it'd be beneficial to move the parity drive to a SATA III port on a PCIE card?

[testdasi]

1 hour ago, CowboyRedBeard said:

Do you think it'd be beneficial to move the parity drive to a SATA III port on a PCIE card?

Generally speaking, reading from array data disks should be a more frequent activity than reading / writing to parity. So I would assume it's better to keep the array on the fast ports as much as possible.

[CowboyRedBeard]

So is a PCIE SATA 3 not going to gain any real speed over an on-board SATA 2?  Or is that speed increase lost via having multiple drives?

[testdasi]

2 hours ago, CowboyRedBeard said:

So is a PCIE SATA 3 not going to gain any real speed over an on-board SATA 2?  Or is that speed increase lost via having multiple drives?

Spinners? Not at all. SATAII effective max throughput is about 280MB/s and that was tested on an SSD. None of my 7200rpm can get past 250MB/s and only for the fist TB or so, still within SATAII throughput.