PCIe x2 twice as fast as x1?

ambush

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Jan 13, 2002
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I'm in the market for an 8-port PCIe SATA III adapter card, which I'll use in JBOD mode rather than RAID. I only wanted 6 ports, but I couldn't find such. I found one card that requires an x1 slot and another that requires x2 (or more, of course). I can use either card in my current system, which has two x1 and one x16 slots open..

They both cost nearly the same. Which should I choose? Would the x2 provide significantly better performance?

Thanks!
 
Solution
that is interesting. looking deeper it looks like the card is designed to need 2 pcie lanes. hence the x2 in the specs. so it would need an x4 slot or better to run full speed.

so the x1 card using only 1 lane would be half as fast as the x2 one using 2 lanes. the more of the sata ports you use, the more the difference will effect performance. so looks like the x2 card would be the better way to go since it sounds like you are planning on using a good bit of the ports.
can you link the cards you are looking at? there are no x2 slots and i suspect that one actually refers to gen 2 slot. slots are multiples of 4 usually. x1,x4,x8,x16 i've never seen an x2 slot.

a pcie 3.0 slot is twice as fast as a pcie 2.0 slot which is twice as fast as a pcie 1.0 slot assuming they all have the same number of lanes. the lanes is the x1,x4,x8,x16 part of the specs.

question is, what type of slots does your motherboard have. the slots are backward and forward compatible but the slot will make a difference on performance expected.
 
Hey, thanks for your reply!

I was puzzled by the reference to x2 as well, but here's a link to the product on Amazon (I'm actually considering a used one): IO Crest 8-port SATA III PCIe 2.0 x2 Controller Card. The x2 is right there in the product's name, although I realize there are no x2 PCIe slots per se.

My ASUS Z87-A mobo has the following slots:

2 x PCI Express 3.0/2.0 x16 slots (single at x16 or dual at x8/x8 mode)
1 x PCI Express 2.0 x16 slot (max. at x2 mode, compatible with PCIe x1 and x2 devices)
2 x PCI Express 2.0 x1 slots
2 x PCI slots

So I'm still left wondering if that x2 card has any speed/performance advantages over the x1 card. The x1 card is also PCIe v2.0 What do you think?




 
that is interesting. looking deeper it looks like the card is designed to need 2 pcie lanes. hence the x2 in the specs. so it would need an x4 slot or better to run full speed.

so the x1 card using only 1 lane would be half as fast as the x2 one using 2 lanes. the more of the sata ports you use, the more the difference will effect performance. so looks like the x2 card would be the better way to go since it sounds like you are planning on using a good bit of the ports.
 
Solution
That's what I was thinking, but I wasn't certain. Thanks very much!