On a card like this you have to figure out who makes it for HP
In this case an indepth search reveals that this is an Emulex card.
We do have Emulex driver but I am unsure if this card is supported.
Looking at this post it don't look good:
Hello, I have installed FreeNAS 11.2U6 on one of my machines - but the HP NC550SFP does not show up after the install. It is initialized during the boot, but seems like the driver is not catching it. Please help :)
www.truenas.com
But I don't see jgreco telling the user to load the firmware on boot.
That is usually required on 10G cards.
/boot/loader.conf
if_oce_load="YES"
This setting is found on the manpage for Emulex OneConnect card.
www.freebsd.org
I am unsure if your HP card is a OneConnect device at heart.
There is also a older Emulex driver for Fiber Channel Storage cards but I dont think the NC550SFP is that device.
www.freebsd.org
The key to your question is to find the underlaying OEM device and use its drivers.
HP does not manufacture cards they simply rebrand them.
According to this post the HP NC550SFP is indeed a OneConnect device. So there is a driver for that.
Maybe it will work. Buy just one and see.... For twenty $USD you wont find a 10G card much cheaper.
I have a couple questions about the oce driver. The cards are HP NC550SFP 10 gigabit dual adapters, which are really Emulex OneConnect devices. FreeBSD server is an older IBM x3650 server. 1: I don't see oce anywhere in FreeBSD 9.x. Has it been dropped or is Emulex being slow in getting a...
forums.freebsd.org
Personally I like jgreco's advice. Buy Chelsio. T-3 cards are pretty cheap.
Do remember that most older cards require alot of cooling.