russell@kings.co.uk (Russell Brown) (06/07/90)
Summary: my shiny new 25Mhz 486/ISC/1542A system is not very fast :-(
Configuration: Elite Group 486 motherboard 8Mb 80nS RAM
Adaptec 1542A (Version 3.07)
Micropolis SCSI 380 Mb Drive.
AMI BIOS (486 v1.1 042790)
Oak VGA Card (came with the box!)
Problems: Firstly, if I set the DMA speed to over 5Mb the system
crashes with On Board Parity Error when accessing the 1542. Addresses
reported vary from 0x1954 ot 0x8478. Any Ideas?? I assume that this
message is from the BIOS but I don't know that - does the Adaptec
generate such messages? Is this the Adaptec or the Motherboard or the
Chipset settings? The board docs say it is rated for 8Mb DMA.
Speed: When running with the DMA speed at 5Mb the beasty is not
significantly faster than my Altos Series 1000 (16Mhz 386 & SCSI).
For example, compiling a moderately size program takes around 2 minutes
on the Altos and 1 minute 50 seconds on the 486 :-( I really did expect
more of an improvement than this :-(
Can anyone help by pointing me in the right direction to try and find
out what is slowing things up (yes both systems were tested in the same
state of load).
Should I be playing with the ISC kernel configuration? if so what
areas? Is there something wrong with the Adaptec setup? how can I fix
it?
In other words HELP!
--
-------------------------------------------------------------------------
| Russell Brown | Voice: +44 832 272224 |
| Lady Lodge Systems | EMAIL: russell@kings.co.uk |
| Chapel Row Cottage, Lutton | UUCP: mcvax!ukc!{stc,logitek}!\ |
| Peterborough, PE8 5NE, England. | kings!russell |
-------------------------------------------------------------------------neese@adaptex.UUCP (06/10/90)
>/* ---------- "486 Speed (or lack thereof...)" ---------- */ >Summary: my shiny new 25Mhz 486/ISC/1542A system is not very fast :-( > >Configuration: Elite Group 486 motherboard 8Mb 80nS RAM > Adaptec 1542A (Version 3.07) > Micropolis SCSI 380 Mb Drive. > AMI BIOS (486 v1.1 042790) > Oak VGA Card (came with the box!) > >Problems: Firstly, if I set the DMA speed to over 5Mb the system >crashes with On Board Parity Error when accessing the 1542. Addresses >reported vary from 0x1954 ot 0x8478. Any Ideas?? I assume that this >message is from the BIOS but I don't know that - does the Adaptec >generate such messages? The parity error message is generated from the system BIOS rom. >Is this the Adaptec or the Motherboard or the Chipset settings? The board >docs say it is rated for 8Mb DMA. The error is caused by the mother board design. There are three areas that could cause this error. 1) If the motherboard memory logic, as provided on the AT bus, has been artificially slowed down, then this error may occur. 2) If IOCHRDY has not been implemented correctly this error could be shown. Overdriving IOCHRDY will slow down the 154x faster than anything. 3) The VGA card may be the culprit as well. Video cards have memory that the system must address. If the memory design of the video card is such that it requires very long memory signals to work poperly, then this would slow down the 154x adapter as well. Especially if the manufacturer has taken this into account and has done 1). >Speed: When running with the DMA speed at 5Mb the beasty is not >significantly faster than my Altos Series 1000 (16Mhz 386 & SCSI). Have you tried adding the synchronous jumper to the 154x board? This would help throughput. Is the Micropolis read ahead enabled? Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ uunet!swbatl!texbell! {cpe,merch,nominil}!adaptex!neese uunet!mlite!adaptex!neese