On Wed, Oct 09, 2002, Adir Abraham wrote about "Re: Linux + Internet by Kvalim": > USB connection uses a lot of CPU resources (try to move your mouse for a > few seconds while you print to a USB printer, and see the differences).
Is this a basic flaw in the hardware design, or simply faulty drivers that, say, set up so they get an interrupt on every bit sent over the serial bus? Does the name Universal *Serial* Bus mean that the CPU has to push data onto the bus bit-by-bit? If so, I can under why it can be slow; In the PCI (Peripheral Component Interconnect) bus used on PCs, for example, the CPU can push 32 or 64 bits into the bus at a time. Moreover, for high-bandwidth using devices such as network cards, DMA (direct memory access) is normally used so that the CPU does not need to get involved in the bulk transfer at all - it is only interrupted when data is ready or when the card's buffers have more room. Does USB have none of these features? (as you can see, I don't really know much about the USB technology). -- Nadav Har'El | Wednesday, Oct 9 2002, 4 Heshvan 5763 [EMAIL PROTECTED] |----------------------------------------- Phone: +972-53-245868, ICQ 13349191 |This box was intentionally left blank. http://nadav.harel.org.il | ================================================================= To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
