Seeking Skylake El Capitan Raid 0 Advice

[stemayer]

Hi,

I am a senior computer programmer and I have built 3 Window rigs in the past and been very happy with them, but I work on Mac these days and need a new high end developer machine. In my quest for ultimate machine performance I want to run 3x Samsung 950 Pro M.2 512GB NVMe in RAID 0 on something like the ASRock Z170 Extreme+.

I see a lot of mixed messages around RAID 0 and being able to boot from it. Apparently to boot from RAID I need the controller (Intel RST) to be in the UEFI/BIOS, which this motherboard has. But from other posts I see that this still will not work as OS X does not allow this to work with the South Bridge chipset. Then I see others giving complicated solutions that say this is how you boot a Hackintosh from RAID 0. Finally they say you will need a Dedicated Hardware RAID Card.

Questions:
1) Can I RAID 0 these 3 drives on the Intel RST in the UEFI/BIOS and boot OS X?
2) Can I boot from 1 of the drives, and RAID 0 the other 2 drives on the Intel RST in the UEFI/BIOS?
3) Can I boot from 1 of the drives, and Software RAID 0 the other 2 drives?
4) What are options for known working Dedicated Hardware RAID Cards?

As this is a greenfield build I am open to other options for screaming fast storage.

Thanks in advance.

 

[Going Bald]

Hi,

I am a senior computer programmer and I have built 3 Window rigs in the past and been very happy with them, but I work on Mac these days and need a new high end developer machine. In my quest for ultimate machine performance I want to run 3x Samsung 950 Pro M.2 512GB NVMe in RAID 0 on something like the ASRock Z170 Extreme+.

I see a lot of mixed messages around RAID 0 and being able to boot from it. Apparently to boot from RAID I need the controller (Intel RST) to be in the UEFI/BIOS, which this motherboard has. But from other posts I see that this still will not work as OS X does not allow this to work with the South Bridge chipset. Then I see others giving complicated solutions that say this is how you boot a Hackintosh from RAID 0. Finally they say you will need a Dedicated Hardware RAID Card.

Questions:
1) Can I RAID 0 these 3 drives on the Intel RST in the UEFI/BIOS and boot OS X?
2) Can I boot from 1 of the drives, and RAID 0 the other 2 drives on the Intel RST in the UEFI/BIOS?
3) Can I boot from 1 of the drives, and Software RAID 0 the other 2 drives?
4) What are options for known working Dedicated Hardware RAID Cards?

As this is a greenfield build I am open to other options for screaming fast storage.

Thanks in advance.

If you must RAID0, suggest additional hardware:

1 each BPLUS M2P4S adapter card - http://www.amazon.com/dp/B00KHMTER6/?tag=tonymacx86com-20

1 each cable set to PCIe BPLUS KZ-B23X4 - https://www.ramcity.com.au/buy/bplus-cable-for-m2p4s-m.2-pcie-3.0-x4-adapter-card/KZ-B23X4
This is only place I have found as source for this cable set.

Setup:
SSD in board M.2 slot, 2 SSD on the PCIe card, PCIe card in last slot with cable set connector in PCIeX4 slot next to it

I do not know if you can then RAID all 3, but you can definitely RAID the 2 on the PCIe card. See post #34 at http://www.tonymacx86.com/mountain-...-os-x-10-8-5-using-tonymacx86-tool-set-4.html for speed of 2 samsung XP941s in RAID on this setup. NVMe should be even faster.
If RAID all 3 not possible, suggest the boot drive be the one in the board M.2 slot.

Alternant, if you have plenty of PCIe slots and only plan on 1 GPU, use 3 each single m.2 to PCIe cards.
Chances of RAID set of 3 SSDs is better with this alternate.

Dedicated RAID cards I cannot advise - have never used one as I consider a RAID boot drive, especially RAID0 to be asking for trouble.


EDIT: You might also consider the Asrock U2 kit - http://forum.asrock.com/forum_posts.asp?TID=490&title=asrocks-front-usb-31-panel-and-u2-kit

 

[stemayer]

So I finally got my machine built and have been working out the kinks on both the hardware and software side. I am up to the point where I have 3 Samsung 950 pros, 2 on the mother board and one on a PCIe x4 slot. I use the NVMe Kext hack from RehabMan to get that far. They are formatted OS X Extended (Journaled) GUID Partition Map. I used "diskutil list" to see that my 3 drives are disk0 disk1 disk2. So I thought all I needed to do was this:

diskutil AppleRAID create RAID0 JHFS+ disk0 disk1 disk2

Unfortunately that gives me the following error:

disk0 does not appear to be a valid file system format
Use diskutil listFilesystems to view a list of supported file systems
Error creating RAID: POSIX reports: Invalid argument(22)

It says this for whichever disk I put first or if I just make up a fake disk name or add the /dev in front or the trailing s2.

Any thoughts on what I might be missing here?

Thanks,
Steve

 

[stemayer]

I tried Softraid and that just worked. Not sure what is going wrong with AppleRAID but I got some impressive results.

 

[pastrychef]

I would have expected better performance. Here's what I get on a single M.2.

The following article also shows much better performance using multiple M.2s:
Amfeltec Squid x16 PCIe board + four SM951s

 

[stemayer]

So I bought that board and I have 4x 950 pro NVMe drives installed on it. I am really hoping to see some great speeds out of these drives. BUT, I can see them in Disk Utility. Any thoughts?

Edit:
Forgot this step: https://github.com/RehabMan/patch-nvme

 

[stemayer]

Strange results. I am getting lower speeds than before with the same 3 drives in the array. Oddly the read side was capping at exactly 2000.0. The write side was just over 1700. Strange. I set up a RAM Disk and tested that. Both read and write were at exactly 2000.0.

I need to get the test tool straightened out before I can play with raid configurations and test speeds properly.

Any thoughts?

 

[kiiroaka]

I've also read that RAID 0 SSDs are not as fast as a single SSD. Years ago some SSDs were not enabling TRIM in RAID 0.

 

[stemayer]

So the article above managed to do this. They got close to 6GB/s, which may be the theoretical limit. I am also stuck at this exact 2000.0 MB/s when I set up a RAM Drive, for both read and write. I tried my own tests with the RAM Drive as the source or destination and timed the reads and writes from the drives manually. The results did not totally make sense there either.

Something is slow here and I need to find out what it is. This RAID-0 Array is the cornerstone of my build. Screaming fast disk access is what will set this apart from a Mac that I could just buy.

I am struggling even to find a place to start with this. Here are the results that I was getting from my manual testing:

in MB/s Write/Read
SSD 410/384
Single M2 898/1380
RAID-0 x2 M2 = 1756/1736
RAID-0 x3 M2 = 1368/1375
RAID-0 x4 M2 = 1799/1485

I am using SoftRAID to make the array. I can't get AppleRAID to do it.

If anyone has suggestions, I am all ears.

Thanks,
Steve

 

[stemayer]

I've also read that RAID 0 SSDs are not as fast as a single SSD. Years ago some SSDs were not enabling TRIM in RAID 0.

The setting "Use TRIM commands on all SSDs" is set in the preferences of SoftRAID.