USB 3.0 card in PCI Express v1 slot

[damole]

hi

I've just revived my older 'retired' gaming PC with Windows 8 Pro and it's making a decent development server/machine.

It's based on an Asus P5B WiFi Deluxe motherboard with an Sapphire ATI HD4850 VGA card.

I'd like to add USB 3.0 but as the motherboard is only PCI Express v1 I'm not sure if the cards I've been looking for would be compatible or gain any speed improvement over USB 2.0 given the bus speed for PCIe v1.

I'm in Asia so I don't have access to all the cards available in the US and European market but I have found this Orico card. It's says it conforms to PCIe v2.0 standard but that's not saying it's not backwards compatible.

Any thoughts?

--damole

 

[Insert_Nickname]

Hello and welcome to the forums.

Putting a PCIe 2.0 card in a PCIe 1.0/1.1 slot will halve bandwidth. So instead of getting 500MB/s you get 250MB/s. It not that big a deal as its still WAY faster then USB2 (somewhere around 25-30MB/s on a good day).

Hope it helps...

 

[damole]

Thanks for the reply.

I'm in Thailand and there isn't so much choice of cards, Orico seems to be the only 'brand name' card available here so I've decided to wait for the next home visit to the UK in summer and I'll pick one up from EBay.

cheers
damole

 

[vailr]

Hello and welcome to the forums.

Putting a PCIe 2.0 card in a PCIe 1.0/1.1 slot will halve bandwidth. So instead of getting 500MB/s you get 250MB/s. It not that big a deal as its still WAY faster then USB2 (somewhere around 25-30MB/s on a good day).

Hope it helps...

Incorrect: you're confusing 2 different standards going by similar sounding names. PCIe cards are now mostly designed according to the PCIe 2.0 or 2.1 standard, with the exception of some of the latest generation PCIe 3.0 video cards that are available. But those version 3.0 video cards can only operate at PCIe 3.0 speeds when used in a latest generation Intel Z77 chipset motherboard. Those same video cards can work in earlier chipset motherboards, but will be slowed down to 2.0/2.1 speeds.
However: PCIe slots are available in PCIe 1x, 4x, 8x & 16x sizes. The 8x & 16x slots are physically the same, but can differ according to the motherboard chipset resources that are available.
To answer the OP's question: a PCIe (v. 2.0) USB 3.0 add-in card should indeed function at full speed when inserted into a PCIe 1x slot. The best USB 3.0 chipset for such a card seems to be made by NEC/Renesas.
Also: there do exist USB 3.0 add-in cards that utilize the older PCI card design. Those would see a speed downgrade, if compared with one of the newer PCIe cards.

 

[Insert_Nickname]

Incorrect: you're confusing 2 different standards going by similar sounding names. PCIe cards are now mostly designed according to the PCIe 2.0 or 2.1 standard, with the exception of some of the latest generation PCIe 3.0 video cards that are available. But those version 3.0 video cards can only operate at PCIe 3.0 speeds when used in a latest generation Intel Z77 chipset motherboard. Those same video cards can work in earlier chipset motherboards, but will be slowed down to 2.0/2.1 speeds.
However: PCIe slots are available in PCIe 1x, 4x, 8x & 16x sizes. The 8x & 16x slots are physically the same, but can differ according to the motherboard chipset resources that are available.
To answer the OP's question: a PCIe (v. 2.0) USB 3.0 add-in card should indeed function at full speed when inserted into a PCIe 1x slot. The best USB 3.0 chipset for such a card seems to be made by NEC/Renesas.
Also: there do exist USB 3.0 add-in cards that utilize the older PCI card design. Those would see a speed downgrade, if compared with one of the newer PCIe cards.

No sir. You are incorrect. PCIe slots are named x1, x2 etc. But the signalling/coding used is different for version 1.1, 2.0 and 3.0 slots. A PCIe 1.1 x1 slot will have 250MB/s available bandwidth. A PCIe 2.0 x1 slot has 500MB/s available and finally a PCIe 3.0 x1 slot has 1000MB/s available...

Multiply where applicable. A PCIe 1.1 x16 slot has a bandwidth of 4000MB/s, A PCIe 2.0 x16 slot has 8000MB/s.

http://en.wikipedia.org/wiki/PCIe