IO Crest Syba 8 Port SATA III Non-RAID PCI-e x4 Controller Card Supports FreeNAS and ZFS RAID - Includes Mini SAS to SATA Breack Out Cables (SI-PEX40137)

Although this controller claims to be PCIe x4 and has a x4 connector, the PCIe switch chip it uses (ASMedia ASM1806) actually has only two PCIe lanes for its upstream link (to the computer) and four PCIe lanes for downstream links (to the SATA controllers). Each Marvell controller is connected by a single PCIe x1 lane, so has a maximum link speed of 500MB/sec (with PCIe v2.0). However, according to Linux's 'lspci' command, the upstream link, although connected at x2, had downgraded link speed to 250MB/sec, so was the same speed as if it was x1.If you're intending to run multiple SATA SSDs on this card for use in a ZFS RAIDZ volume, as I was, there will be a bottleneck when attempting to read or write to more then two devices. I ran a test with 'dd' reading data from one SSD and it sustained 407MB/sec. As soon as I started a second concurrent 'dd' from a second SSD, the throughput of each was only about 210MB/sec. The same thing happened when the two test SSDs were connected to different Marvell controllers. The same pair of SSDs sustained about 550MB/sec each at the same time when connected to an LSI 9211 controller.

Got it for my Freenas setup works great 😊

buyer beware these cards are not UEFI compliant so you will need to...1. run the CSM blob and load bios OptionROM's (to boot from drives on the card)2. use these for storage only and boot from a separate driveThen we come down to the numerous issues that have been reported with these cards.Basically to get these to work correctly you need to disable IOMMU (either on the kernel command line with iommu=off) or in your BIOS/UEFI screen.Enabling Virtualization extensions and IOMMU will cause this card to freak out due to DMA errors, without IOMMU enabled it works fine.The "PCI-e x4" support is misleading, the 88SE9215 chip used as a SATA controller in these cards only supports PCI-e x1 link speeds (as per the datasheet). So if you are thinking (like I did) that you'll grab this and setup a sweet 8 drive SSD ZFS pool you would be better off with using your on-board controller or just using regular hard drives.I've tested these with Linux kernel versions 4.19, 5.4 5.7 and 5.8 and they seem to work oob on the standard ahci driver (minus the IOMMU tweak above), surprisingly this card also seems to work with macOS (10.15.7) with no issues.For the price, I'd say it prevented me from returning it for a more expensive LSI card and it does work...I just wish I could enable IOMMU so I could use this in conjuction with ZFS ZVOL's and KVM and hardware passthrutl;dr: turn off IOMMU if you have CPU virtualization turned on, enable the OptionROM loading option if you want to boot from drives on the controller.

Yes, This thing is a second generation PCI Express 2.0 card. Yes, you can plug it into a PCIe 16 card slot. Works fine. Now, the question is then, why does that make sense? Because I have no need for a graphics card on my FreeNAS 11.3 motherboard. Booted FreeNAS and the card with it's drives were recognized without a whimper. My MB? Gigabyte B250 with a 4th gen Intel I7 and 32mb of RAM. Stuff that was laying around are now chewing up electrons and providing a nice home server that has been running amazing well on 4+1 RaidZ2. I love ZFS. Marvell got knocks for its HBA cards not talking to FreeNAS. This card from Syba was worth a try. You should try it too.

I am running a Truenas server and this is perfect. Plug in and no issues. No software needed. Very fast. I am very pleased.