Archived from groups: comp.sys.ibm.pc.hardware.storage (
More info?)
In article <2gd2g1F1e6vmU2@uni-berlin.de>,
Folkert Rienstra <folkertdotrienstra@freeler.nl> wrote:
>
>"Al Dykes" <adykes@panix.com> wrote in message news:c7r1hq$df6$1@panix3.panix.com...
>> In article <40a1053f.69354816@news-server.houston.rr.com>,
>> Bob <spam@spam.com> wrote:
>> > On 11 May 2004 11:22:14 -0400, adykes@panix.com (Al Dykes) wrote:
>> >
>> >> You can buy a PCI IDE card with 2 channels and put your optical disks
>> >> to that.
>> >
>> > I thought modern computers came with 2 IDE channels on the mainboard.
>> > That's 4 devices.
>> >
>> >
>>
>> yea, but it's not 4 channels, and if you mix a fast and a slow
>> device on a channel it slows down to the speed of the slower one.
>
>Obviously not.
>When the slow drive has the bus the other drive isn't doing anything, obviously.
If you put a DMA and a non-DMA capable device on an interface the drivers
dumbs down to the lower one, right ? That's what I'm refering to.
>
>If and how much slowdown is experienced is decided by the duty cycle of the 2
>devices, the bandwidth that they actually need and at what busspeed they run.
>
An optimal system/application configuration wuld spread disk activity
across both disks. One way to do this is to set them uup as RAID0
(striping).
>>
>> A PCI IDE card is only a few bucks.
>>
>> Contention between two disks on a channel might be a bottleneck for
>> your application, but the only way to tell for sure is to use a tool
>> like perfmon.exe (part of NT) to see what your system is doing.
>
>And what will that tell you?
>
Perfom will allow you to determine where the bottleneck is in your
system when you are running your application and wishing it would go
faster. It may be that you need a faster CPU, more memory, or
faster disk I/O. If you have more than one disk it will show you
which disk is working hardest.
--
Al Dykes
-----------
adykes at p a n i x . c o m