Re: PCIe 3.0 8 port SATA 6 Gbps HBA for SOHO network

On Fri, Mar 18, 2022 at 1:01 AM David Christensen wrote:
> I have a SOHO network with various x86_64 servers/ workstations/
> desktops (FreeBSD, Debian, Windows) and an assortment of phones/ pads/
> pods/ televisions/ game consoles, etc..  I would like to add more SATA 6
> Gbps HDD's and/or SSD's to the x86_64 machines and am looking for a
> suitable PCIe 3.0 8 port SATA 6 Gbps host bus adapter (non-RAID).
>
> The LSI® SAS 9207-8i PCI Express® to 6Gb/s Serial Attached SCSI (SAS)
> Host Bus Adapter looks appealing:
>
> https://docs.broadcom.com/doc/12353331
>
> Comments or suggestions?
> David

Hello David :-)

1. PCI-E 3.0 x8 card may not achieve full 8 * 6Gbps as it close to
7.877GB/s bus limits (according to [1]). If speed is not crucial this
card looks really nice may give plenty of storage at decent price. I
never used it but may also buy one  :-)

2. If speed is crucial then you may consider M2 NVM controller for
newer SSD devices that are faster than SATA. Such controller works
with FreeBSD even on a motherboards with no NVM support in BIOS but
you need to boot and run kernel from a bios compatible device then use
nvm as root. Some newer motherboards may have no M2 NVM slot but
support for NVM in BIOS so you can boot directly from PCI-E NVM
controller in that case.

3. Real PCI-E speed depends on chipset. Older motherboard that I had
with AMD 970/SB950 chipset had 500MB/s limit for
Ethernet/SATA/PCI-Ex1, while only replacing motherboard to AMD 990FX
chipset gave 1GB/s with no problem, both are PCI-E 2.0 in theory.

[1] https://en.wikipedia.org/wiki/PCI_Express

-- 
CeDeROM, SQ7MHZ, http://www.tomek.cedro.info