Hi Homelab community, After spending lot of time on unraid and homelab subreddits, I finally decided to host a NAS and started purchasing hardware. I bought 8 x 8tb drives(6+2parity drive+ 2 spares) but having trouble finding a motherboards which support 2 pcie x8 cards. All the boards I am checking on Newegg have 1 x16, 1 x4(mechanically x16), couple of x1(some boards have mechanically x16 slots but electrically 3+ slots are x1) Seems like I am missing something as I couldn’t be the first person who is looking to use 2 pcie slots. I want to use an HBA card (requires one x8 slot) and dual 10gbps nic (requires one x8 slot)

I am open to AMD/Intel though leaning more on Intel due to qsv i5-12600k + LGA 1700 motherboard Or 7600 + AM5 motherboard

Any help would be appreciated

  • oprivacy@alien.topOPB
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    1 year ago

    Bingo!!

    I will check the board manual for confirmation.

    Reg why I am looking for x8 slot is that all the dual 10gbps cards I found are pcie3 x8. Can I use an x8 card in x4 electronic slot and will it have half max bandwidth ie 4GB/s instead of 8GB/s? or system doesn’t recognize it?

    • Logicail@alien.topB
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      1 year ago

      PCIe is forwards and backwards compatible, so you can use a 3.0 card in a 2.0 slot or vice versa but if the board doesn’t have physically 8x or 16x slots it can require opening the end of the slot.

      A lot of 10gbps NICs are 3.0 8x, but I think that is likely so that they still operated at full speed even in 2.0 slots which were probably more common ~10 years ago when such cards were new.

      Apart from boards with two x8 slots it could be an option to go with a cheaper 16+4 board, HBA + NIC. With the HBA in the future you could add a SAS expander for more drives plus there are the onboard ones - some expanders can be powered via the PSU and don’t need a PCIe slot.

      For the sake of $100-150 I would probably go with a board with two 8x ports, it gives more flexibility in the future such as the option of a second HBA instead of an expander.

      Looking into the ASRock Z790 Taichi Lite and it’s predecessor a little more feature/spec wise it appears they are identical and the difference is cosmetic, losing some RGB and heatsink mass/covers.