Mark Knecht <markknecht@xxxxxxxxx> writes: > On Thu, 21 Oct 2004 19:43:16 +0100, anahata <anahata@xxxxxxxxxxxxxx> wrote: >> On Thu, Oct 21, 2004 at 07:44:11PM +0200, David Baron wrote: >> > was told that the slower CD device will slow down the HD. >> It used to be true. It was often misrepresented as the CD slowing the HD >> down to its speed > No - this actually is true. An EIDE controller that is compliant with > the ATAPI specs will recognie that one drive operates with the cable > going 100MHz, while the controller recognizes that the CDROM only > works when the cable goes 33MHz or 66MHz. since the two drives are on > the same cable the EIDE controller sets the cable speed at 33MHz and > therefore you get less throughput from the hard drive. I wasn't aware > until about 2 years ago that the controller had to do this. There are > some good white papers somewhere on the Seagate or Maxtors sites if I > remember correctly. So you say, that it is the *controller* who does it? It can not be influenced (set) by the kernel, by hdparm or something? This sounds like it could be easy to figure it out with dmesg, hdparm or something comparing results with and without connecting the optical drive? What exactly should i look for? Robert
