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 Solvedgpu not working with PCI x16 speed slot Forum Is it worth using a PCI-E 2.0 Graphics Card on a 2.0 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 SolvedDumb Question - Small PCI-E (wifi card) in a full PCI-e slot? Forum 2nd PCI express slot runs @ 8X when using SLI? Forum Half pci device in a full pci slot? Forum SolvedGTX 770 2x8-pin connectors, only 1 PCI-E slot on PSU 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 SolvedWill a PCI e 3.0 GTX 750 work on my motherboards PCI E 2.0 slot Forum SolvedAnyway to use PCI card in PCIe slot? Forum Solvedhow to know my GPU slot is PCI E × 16(2.0 OR 3.0) Forum SolvedWill a R9 270x which a PCI-E 3.0 card apply to a PCI-E 2.0 slot? Forum Solvedcan a usb3 hard drive be used on laptop with usb2 connector Forum More resources Read discussions in other Motherboards categories BIOS Boot Chipsets ASRock Asus Chaintech DFI Elitegroup FIC Foxconn Gigabyte Intel MSI-Microstar !