--On Wednesday, June 02, 2004 18:48:46 -0400 Jon LaBadie <[EMAIL PROTECTED]> wrote:
> On Wed, Jun 02, 2004 at 04:21:35PM -0600, Glenn English wrote: >> On Wed, 2004-06-02 at 14:12, Gene Heskett wrote: >> >> > Any current ide drive can do 30+ Mb/sec if left >> > alone by other tasks, often quite a ways on the + side. >> >> Is that just a burst out of the cache, or can they read dis-contiguous >> files, seek around to other files, wait for latency, and write all at >> the same time that fast? Or even half that fast? If so, and if Linux and >> Intel's IDE controllers lose another 25% moving bits around, it'd still >> be comfortably faster than the tape drive. I think I may have something >> horribly misconfigured. > > On Solaris x86, one thing that terribly degrades IDE disk > performance is if the driver does not use dma but uses pio mode. > There are even reports of diagnostic tools saying the drive is > using dma, but digging deeper determines that pio mode is in use. > > I know not how to check or configure the HD driver on linux, > but it might be something to check. If it's linux, try using hdparm to verify the modes and speed of your disk. Like Jon says, a good drive can have terrible performance if it is running in the wrong mode. Also, make sure your kernel is using the correct chipset driver for your IDE controller. On a machine at home I replaced the motherboard and my disk speeds dropped to under 2MB/sec. I finally figured out that since I had a different controller than the one I had compiled in support for, the kernel had dropeed back to generic IDE support. Rebuilding the kernel with the proper driver made an over 10X performance boost. Frank > > -- > Jon H. LaBadie [EMAIL PROTECTED] > JG Computing > 4455 Province Line Road (609) 252-0159 > Princeton, NJ 08540-4322 (609) 683-7220 (fax) -- Frank Smith [EMAIL PROTECTED] Sr. Systems Administrator Voice: 512-374-4673 Hoover's Online Fax: 512-374-4501
