Re: Mixed controllers on JBOD Raid 6?

[Roman Mamedov <rm@romanrm.net>]

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On Wed, 1 Jul 2015 19:27:11 +0100
Another Sillyname <anothersname@googlemail.com> wrote:

> I'm looking at an Asus Maximus Vii Gene motherboard which has 8 SATA
> controller connectors.....6 Intel and 2 other (can't remember at the
> moment).
> 
> Are there any projected issues or concerns about making a 8 Drive
> RAID6 array where I'm using mixed controllers?

Mixing controllers in general -- no issue whatsoever, that's the beauty of the
(Linux) software RAID.

In cases like yours, there could be a minor performance hit if the additional
2-port controller gets fed only a single-lane of PCI-E 1.0. If so, this will
cap the total throughput of both ports combined to less than 250 MB/sec.

However on the motherboard that you specified that controller is ASMedia
ASM1061 which supports PCI-E 1x 2.0. And if the chipset really provides a 2.0
port to it (not an expert in Intel chipsets, check the datasheets), then the
cap would be 500 MB/sec, which should be more than enough for two regular
spinning hard drives.

In any case, typically with RAID6 setups like these getting the highest
possible sequential read/write performance isn't on top of the priorities
list, so the above may not even be a concern for you.

-- 
With respect,
Roman

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