Motherboard settings question: How can my SATA settings use AHCI and RAID at the same time?

Eggz

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Hi Tom's People,

Just like the title asks . . . I want to run a fairly common setup as efficiently as possible; namely an SSD containing my OS and programs with two HDDs in RAID1 for media and other mass storage.

Can my motherboard (Asus Rampage IV Gene) support an SSD in AHCI and a pair of HDDs in RAID1? Here are the drives I'll be using if that helps:

SSD: 1x Samsung 840 EVO 750 GB
HDD: 2x Seagate Constellation ES.3 ST4000NM0033 4TB

I'd really appreciate help from those of you who have experience with running a single SDD and 2 HDDs in a RAID1 configuration on a single system. The only thing I've found online about this topic was from a similar thread on Tom's but for a different motherboard (click for link). Perhaps it's possible to adapt a solution like the one selected in that thread but for my motherboard? Not sure.

The reason I ask is because I like that AHCI allows my SSD to control itself internally while retaining trim capability. At the same time, I also need RAID1 for increased fault tolerance.

Can I make both work together? Maybe using different controllers on my motherboard will help. For instance, what about if I use the x79's native SATA 6.0 Gbps controller plugs for the SDD and also ASUS's 3 Gbps controller plugs for the HDDs? I'd imagine the motherboard's SATA setting would be set to RAID either way, but maybe it's possible to configure this with AHCI enabled.

Also, I am not 100% set on any particular mode for my SSD (e.g. AHCI), so suggest away if RAID and AHCI aren't the only two options for my scenario. I just want to retain my SSD's very good internal controls and be sure that trim will continue to work, if at all possible, while running my HDDs in RAID1.

Specific information on this has been hard to find, so please chime in if you've set up something like this before.

Thanks!

P.S. I'm reposting this here because it seems like a motherboard question, and no one answered in the Storage forum. Hope you motherboard experts can help!
 
AHCI is included with the RAID driver. So, loading that up and configuring RAID in the BIOS even on the same controller with get you there. You just don't make the SSD a member of the array (it shows up when I boot as "non-member disk").

I'm running a boot SSD with RAID 1 HDDs and it works fine.
 

FireWire2

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The Best solution is using AHCI
RAID1 both 4TB in Disk management.

This will give you the BEST performance in SSD and most compatible on your RAID1.
If your MB screwed up, just plug these HDD into a new MB, you will see your data... there wont be a compatible issue.

As far performance concern, there is NO different, the host CPU still doing all RAID calculation in either case and RAID1 is very simple RAID

 

Eggz

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Thanks for replying! I think (but am not sure) that's what I have setup. I just put the SATA in RAID mode and installed Intel Rapid Storage. The SSD is not part of the RAID, but the 4TB HDDs are. There is a new screen with disk information at POST, and the array works. I can hot swap the dives but haven't tried them on a different computer, and I only think the SSD is in AHCI because AHCI protocol is part of RAID tech. That make sense?
 

FireWire2

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Yes, it supposes to... but often enough there is screw up in the BIOS and the drivers, can tapper down the performance of SSD..

I would test the SSD speed:
for SSD (3Gb) connection, it should have 200MB+
for SSD (^Gb) connection, it should have 300MB+
If you can get this speed, you are OK, other wise you have latency issue. because an extra layer of RAID drivers on top of AHCI, which may cause this latency
 

Eggz

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Hey, good advice. I always think testing is a good way to go!

So, here is what I got. Seems okay to me. What do you think?

SSD
Sequential read: 261 MB/s
Sequential write: 518 MB/s

Random read:80,000 IOPS
Random write: 84,000 IOPS

HDDs
Sequential read: 96 MB/s
Sequential write: 178 MB/s

Random read:4,300 IOPS
Random write: 788 IOPS
 

Eggz

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Yeah, I thought the reads seemed a little off compared to the writes, so I restarted and ran it again with better luck.

SSD
Sequential read: 304 MB/s average (540 max)
Sequential write: 480 MB/s average (520 max)

Random read:85,000 IOPS
Random write: 86,000 IOPS

HDDs
Sequential read: 93 MB/s
Sequential write: 108 MB/s

Random read:4,000 IOPS
Random write: 559 IOPS