Will I get full speed of USB3 using PCi 2 slot? Tags: Motherboards PCI Bottleneck USB3 Last response: October 26, 2011 5:44 PM in Motherboards Share midi25 October 26, 2011 3:56:02 PM Hi I have purchased a USB 3 Pci2 card. What I want to know is will I get the full speed of USB 3 with PCi2? Will I have any bottlenecks and what is the max throughput of PCi2? Thanks More about : full speed usb3 pci slot itzdanielp a c 121 V Motherboard October 26, 2011 4:38:23 PM You will be media limited far before you saturate the pipeline of a PCIe 2.0 bus. MRFS October 26, 2011 5:44:53 PM A single x1 PCI-E 2.0 lane oscillates at 5 GHz, and each byte has one extra start bit and one extra stop bit, in addition to 8 data bits, OR 10 bits per byte. Thus, 5 GHz / 10 = 500 Megabytes per second in each direction (max bandwidth) per PCIe 2.0 lane. USB 3.0 is 10 TIMES the speed of USB 2.0, or 10 x 480 Megabits per second = 4.8 Gb/sec. http://www.everythingusb.com/superspeed-usb.html Again, each transmitted byte has a start and stop bit + 8 data bits. Thus, 4.8 Gbps / 10 = 480 Megabytes per second. So, the limiting factor is the USB 3.0 bandwidth (480) not the PCI-E 2.0 bandwidth (500). Of course, controller efficiency is a factor too, but no controller can exceed the rated max bandwidth. Hope this helps. MRFS Can't find your answer ? Ask ! Publish Related resources SolvedGTX760 in PCI-E 3 slot, but using PCI-E 2? Forum Solvedis the temp target and power target recommend even i use pci-e 2.0 slot? Forum SolvedWill i lose any performance if I use the radeon r9 280x with pci 3.0 on a 2.0 slot, how much of a difference would the 3.0 slo Forum Is it worth using a PCI-E 2.0 Graphics Card on a 2.0 Slot? Forum Solvedgpu not working with PCI x16 speed slot Forum SolvedHow can I determine the speed of my PCI Express slot? Forum Is there a usb3 card for pci-x slot Forum SolvedWill a usb 3.0 pcie card work at full speed on a pcie 1.0 slot? Forum 2nd PCI express slot runs @ 8X when using SLI? Forum SolvedDumb Question - Small PCI-E (wifi card) in a full PCI-e slot? Forum SolvedDoes PCI Express 3.0 x16 graphics card work on PCI Express 2.0 slot? Forum Half pci device in a full pci slot? Forum Solvedwhat will pci-e 3.0 slot run at with fm2 cpu rather than fm3? Forum Solvedcan i run a PCI 3.0 card in a PCI 2.0 slot Forum Solved3.0 PCI Express Graphics card in 2.0 slot motherboard Forum SolvedGTX 770 2x8-pin connectors, only 1 PCI-E slot on PSU Forum Solvedcan a usb3 hard drive be used on laptop with usb2 connector Forum SolvedWill pci express 3.0 x16 card work in pci 2.0 x16 slot? Forum SolvedHD 7990 on a PCI express 2.0 slot Forum Solved6+2 pin pci-e connector won't go all the way in 6 pin pci-e slot Forum More resources Read discussions in other Motherboards categories BIOS Boot Chipsets ASRock Asus Chaintech DFI Elitegroup FIC Foxconn Gigabyte Intel MSI-Microstar !