Sata Controller Card - x4 or x16?

My motherboard is http://www.gigabyte.com/products/product-page.aspx?pid=4970#sp

Which has a x16, x4 and 2 PCI slots. I have a GeForce 750TI in the x16 slot at the moment.

My motherboard comes with 6 sata ports, which are already full, using 4/5tb drives and 1 ssd, my most economical option is Sata PCIe controller. I feel like I could settle for a 4 port card but would like 8 for future expansion. I should be able to juggle my GPU between the x16 and x4 based on the Sata controller I get?

Most of my storage is Media for Plex, so other than initial writes, most of the time it is only reads.

Anyone have any suggestions for what I am looking for. Browsing over the unRaid hardware comparability guides and posts, most seem to be at least 2-3 years old. Which could be alright if the market hasn't changed much for these things.

Would appreciate any feedback! Thanks in advance!

Your motherboard has PCIe v2 slots, so with 4 lanes you'll have 2000MB/s of bandwidth.    This is enough to support 8 drives with no throttling, so as long as you get a v2 card, an x4 8 port card is fine.

One other note:  ANY card will work just fine for normal operations => the only time there will be throttling of the transfer speeds is when all drives are being used simultaneously and the available bandwidth is less than the total capabilities of the drives ... e.g. during parity checks or drive rebuilds.

But with PCIe v2 slots, an x4 slot won't have that problem with up to 8 drives.

One other note:  ANY card will work just fine for normal operations => the only time there will be throttling of the transfer speeds is when all drives are being used simultaneously and the available bandwidth is less than the total capabilities of the drives ... e.g. during parity checks or drive rebuilds.

 

But with PCIe v2 slots, an x4 slot won't have that problem with up to 8 drives.

Now when you say ANY card, do you mean just the standard PCI slots?

Like Gary mentioned bottleneck will be only during parity check/sync and disk rebuild, but more than x4 or x16 lane controller, your biggest issue will be if use the bottom pcie slot, because it shares the DMI connection with the onboard SATA ports, DMI is 2000MB/s theoretical max but real world is closer to 1500MB/s, so depending on many disks you end up this is max speed you can expect during those operations:

6 onboard + 4 port controller: 145MB/s

6 onboard + 8 port controller: 110MB/s

It won’t matter if controller is x4 or x16.

Here is the motherboard diagram

Yep, that's an issue on most Intel based desktop pre-Skylake boards, exception are boards with SLI support that usually have 2 x8 CPU slots.

I did some tests while ago, and with 14 SSDs sharing the DMI 2.0 during a parity check maximum speed I got was 108MB/s.

.. Now when you say ANY card, do you mean just the standard PCI slots?

NO -- I mean any card in the PCIe x4 slot.    PCI slots have far too little bandwidth.

I went ahead and ordered a AOC-SASLP-MV8 to put in my x4 slot. Anything special I should be aware of as I am installing this?

Should be plug n play.

The AOC-SASLP-MV8 is a very good card which has been very well tested with UnRAID ... there are a LOT of folks using this card.

One note, however:  It's not a PCI v2 card, so it's limited to v1 bus speeds of 250MB/s/lane -- a total of 1000MB/s since it's an x4 card.    With modern high-density drives (like your 5TB drives) a single drive can easily approach 200MB/s on the outer cylinders ... so if you use more than 5 of the ports on this card it will be a bit of a bottleneck during parity checks or drive rebuilds, when all drives are used at once.

Not a problem at all -- it won't slow anything down during normal array operations, and won't have any impact on parity checks or rebuilds unless you attach more than 4 drives to it ... and even then that impact won't be all that dramatic.

Like Gary pointed out the SASLP is somewhat bandwidth limited, I use it myself but with 4 disks max, but many people here use them with 8 and don’t mind the speed, I just want to point out to you or future readers that for some reason this controller (as well as the SAS2LP) performs significantly worse on DMI vs. CPU slot.

This is the maximum parity check/sync speed you can expect depending on the number used disks:

        CPU slot - DMI slot
4          140   -   116
5          117   -    96
6          105   -    82
7           90   -    71
8           80   -    63        

The AOC-SASLP-MV8 is a very good card which has been very well tested with UnRAID ... there are a LOT of folks using this card.

 

One note, however:  It's not a PCI v2 card, so it's limited to v1 bus speeds of 250MB/s/lane -- a total of 1000MB/s since it's an x4 card.    With modern high-density drives (like your 5TB drives) a single drive can easily approach 200MB/s on the outer cylinders ... so if you use more than 5 of the ports on this card it will be a bit of a bottleneck during parity checks or drive rebuilds, when all drives are used at once.

 

Not a problem at all -- it won't slow anything down during normal array operations, and won't have any impact on parity checks or rebuilds unless you attach more than 4 drives to it ... and even then that impact won't be all that dramatic.

Ok, that will be something to consider. I do have an SSD and a couple 4tb drives. I plan to do dual SSD. SSD in the Cache slot, obviously takes it out for parity checks? So would it be smart to move and setup them on there? Would having 4tb vs 5tb make a difference? Max drives are going to be 8 on that card anyways if im not mistaken.

The AOC-SASLP-MV8 is a very good card which has been very well tested with UnRAID ... there are a LOT of folks using this card.

 

One note, however:  It's not a PCI v2 card, so it's limited to v1 bus speeds of 250MB/s/lane -- a total of 1000MB/s since it's an x4 card.    With modern high-density drives (like your 5TB drives) a single drive can easily approach 200MB/s on the outer cylinders ... so if you use more than 5 of the ports on this card it will be a bit of a bottleneck during parity checks or drive rebuilds, when all drives are used at once.

 

Not a problem at all -- it won't slow anything down during normal array operations, and won't have any impact on parity checks or rebuilds unless you attach more than 4 drives to it ... and even then that impact won't be all that dramatic.

 

 

Ok, that will be something to consider. I do have an SSD and a couple 4tb drives. I plan to do dual SSD. SSD in the Cache slot, obviously takes it out for parity checks? So would it be smart to move and setup them on there? Would having 4tb vs 5tb make a difference? Max drives are going to be 8 on that card anyways if im not mistaken.

Whether your drives are 4TB, 5TB, or even larger doesn't matter => the limitation is bandwidth, so what matters is the areal density of the drives.  Most current 4-5 TB drives use 1TB platters -- larger drives are often more dense (1.2 - 1.33 TB platters), so they'd be a bit more constrained by the card ... but would still operate at the same speed as the 4 or 5 TB units.

You're correct that during a parity check the cache drives won't be in use, so they won't be using any of the card's bandwidth (assuming you're not doing something else that is using the cache drives at the same time).

And yes, the card only supports 8 drives, so clearly that's the max 

Bottom line:  It's a very nice card ... you should simply recognize the limitations of it's 4-lane PCIe v1 interface and recognize that this will slow down some array operations -- but in general won't slow anything down in normal use.

Awesome, I got it today, I will start working on it after class and backup my cache drive while in class.

I totally think this will get me by for the next year or so.

So I think i definitely want to put both my SSD's on there. And a "NEW" spare 5tb I have waiting to go in.

Anyone else have any ideas or recommendations for a better setup?

I think I want to clean up my user shares too. I took some screenings. Would anyone mind taking a look and recommendations??

And a copy of my vars? Looked important lol.

unraidVars.txt

I have been working on this sata install most of the night. Having some issues to boot into the Marvell Bios utility just before Windows starts.

I believe there is an issue with a bios settings for my gigabyte board? Some were saying the onboard controller cannot be AHCI? I cannot get it to load either way. I did get it rolling once in windows and can view my test SSD. But any tricks to get the Bios Utlility to Load? Using Cntrl - I or Cntrl - M?

I installed the windows MRU Marvell Raid Utility in Windows, which shows a Firmware version of 3.1.0.0015 and a driver version 3.1.0.0022. Which I believe the firmware you want ver 15?

I couldnt find anywhere to download it, guess i lucked out thats what was loaded.

Thanks

Ok I got it all figured out, there is a lot of information scattered around the forums, had to piece a lot together. But I found out there is no GUI to CTRL - I into for settings on the 15 firmware version. Since there is no Raid support there really isn't a need. I also found out, that the Marvell and Intel controllers like to be smart, and will not even allow your to get into the Bios for raid settings unless you have at least 2 drives connected. Can't raid 1 disk!!!! Lol

I so flashed to the new 21 firmware, checked the txt file before and saw raid was disabled. Upgraded perfectly, and Bios utility prompts me now as I expected. Not to mention both my SAS cables are reading all my disks! I was stoked,

I about shit myself when I finally booted unRaid and took a shower, expecting to lose a drive or 2 or all due to the way I was dicking around with the controller cards settings. I came back to see all my disks spun up, online and Parity was fucking valid!!!!! Hells yea!

I am baller now, working on backing up my plex data of cache, then going to setup my btrfs cache pool. Is there a limit and how many disks we can put in them?

I am baller now, working on backing up my plex data of cache, then going to setup my btrfs cache pool. Is there a limit and how many disks we can put in them?

The limit is the total number of devices your unraid license allows.