Any advantage to nvme hba other than saving pcie slots?

somename

New Member
Nov 11, 2011
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Does 4 port nvme hba have any performance or reliability benefits over using cheapo 4 u.2 to pcie adapters? Assuming sufficiently available pcie lanes of course. TIA
 

NablaSquaredG

Active Member
Aug 17, 2020
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Depends on what you mean by "NVMe HBA"

First, they might lift the requirement of needing PCIe bifurcartion, because there are NVMe HBAs that can split 16 to 4x4 without needing bifurcation by the host.

Second, NVMe HBAs usually to either redriving (the cheapo variant) or retiming of the PCIe signal, thus improving signal quality, reliability and speed which becomes especially important if you have a cable (e.g. SFF8643) between the controller and the SSD and want to use PCIe4.0
 

somename

New Member
Nov 11, 2011
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I was looking at lsi9400 or one of the supermicro options for hba. I wasn't sure if it was better to upgrade my hba or upgrade motherboard+cpu to platform with more pcie lanes and stick 4 pcie to u.2 adapters.

Pcie 4.0 probably won't be in the card for me for a while. I'd want more pcie lanes than in Ryzen 3, and threadripper and Epyc platforms are bit much for my use(freenas). Maybe new 3rd gen scalable might work as it seems they have 8 core version if its power consumption is low enough.

Thanks for your advice.
 

andrewbedia

Active Member
Jan 11, 2013
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I have a pair of Lenovo 530-8i flashed to standard 9400-8i firmware. The NVMe performance was garbage (800MB/s) and it required the proprietary cable from Avago. My advice is save your money and get something from this list I posted. These are simple PCIe cards with PCIe switches. No drivers/configs needed. https://forums.servethehome.com/ind...apters-that-do-not-require-bifurcation.31172/

If you have a bifurcation capable motherboard, look through the supermicro parts catalog and then look them up on ebay.
 

lunadesign

Member
Aug 7, 2013
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For bifurcation capable motherboards, I'm guessing the retimer cards will perform better than going through a card with a PCIe switch, right? Any idea what the difference is?
 

somename

New Member
Nov 11, 2011
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Good to know. Thanks. I actually read through the thread, and I am actually considering those cards. I still wonder though if I should just upgrade my platform to xeon w or xeon bronze and get few of something like these instead. As a bonus, I'd be able to use rdimms instead of udimms(my current freenas box runs xeon e3 v5)
 

NablaSquaredG

Active Member
Aug 17, 2020
225
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For bifurcation capable motherboards, I'm guessing the retimer cards will perform better than going through a card with a PCIe switch, right? Any idea what the difference is?
PCIe switches add a bit of latency, but that's usually negligible (even when you attempted to use a gaming GPU behind a PCIe switch)