Maybe I'm in error: USB 3 drives are not fast enough to fill the entire usb3 bandwith. I have a similar setup, 2008 PC and added the cheapest usb 3 card (renasas chipset) I could find. the usb 3 drives are as fast or slow as the internal sata3 drives.
On 7 July 2015 at 06:23, Larry Colen <[email protected]> wrote: > Might this be a good time to look at finding a more modern mobo? You might be > able to find a used one with usb 3.0 for not much more than a usb 3 card > > On July 6, 2015 8:17:03 PM MST, Mark C <[email protected]> wrote: >>I'm fixing to upgrade my circa 2009 PC with a USB 3.0 card. Knowing >>that >>there are many people here who understand this stuff better than I do - >> >>a few off topic questions... (since the USB card will be used to >>support >>drives that will store photos taken with my Pentax gear, it's not >>completely off topic...) >> >>It seems that you need at least a PCIe 2.0 slot with 5 GBps throughput >>to get full USB 3.0 speed. My PC only has two free PCIe 2.0 x1 slots >>@2.5 GBps each. The sole PCIe 2.0 x16 slot is occupied by the video >>card. There are also a couple free legacy PCI slots - I think they are >>32 bit PCI slots. (The mother board manual simply calls them "PCI >>slots"). >> >>Adding a USB 3.0 card to one of the free PCIe x1 slots seems to be the >>obvious route to go. With PCIe x1 I will only get 50% of the possible >>maximum throughput. Based on what I read - that will still be a good >>bit >>faster than USB 2.0... If USB 3.0 is theoretically 10x faster than USB >> >>2.0, then my theoretical increase will be 5x.... is that right? >> >>Would there be any point in even considering adding a USB 3.0 card to a >> >>legacy PCI slot? As best I can tell PCI has a maximum of 133MB/s or >>roughly 1 GBps so USB 3.0 on a PCI bus could be about twice as fast as >>USB 2.0??? I assume far short of the increase expected from using a >>PCIe >>x1 slot... >> >>As I understand it, each USB controller splits the bandwidth between >>all >>active devices connected to it. So if I am copying files between two >>USB >>drives hooked up to a single USB controller the bandwidth would be >>split >>between them. That makes me wonder - if I add two USB 3.0 cards to my >>PC - one in each of the free PCIe x1 slots - and put one drive on each >>card, will that result in each controller running at full speed when >>copying from drive to drive? That would be as fast as copying between >>two drives on a single controller running off a full speed PCIe 2.0 >>slot. Is my thinking right on that point? Since the USB cards are >>about $20 each, I'd give that a try if it would speed things up. >> >>Lastly - is there anything in particular - e.g. desirable chip sets or >>features or brands to avoid - in USB cards and hubs? (I plan to add at >>least one card and one external hub.) >> >>Thanks! >> >>--- >>This email has been checked for viruses by Avast antivirus software. >>http://www.avast.com > > -- > Sent from my Android phone with K-9 Mail. Please excuse my brevity. > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
