RE: [myrinet] RE: Re: Low bandwidth

Hi,

I would try to move the Myrinet card to slot 7 - the top slot (hopefully 64
bit in your system) and see if anything improves.  I do know the bottom 2
slots will possibly suffer issues with interrupts and overall throughput
since they "share" resources.  

I also did some digging into what is left of the old Digital internal
"notes" areas and confirmed the PCI performance best seen was 111MB/sec DMA
read, and 65MB/sec DMA write.  This was in a 32 bit slot.  I did not find
any data for the 64 bit slot that appeared as the top slot in the later
AS500-400 and -500 machines.

Tim  



-----Original Message-----
From: Francesco Lovergine [mailto:[email protected]]
Sent: Wednesday, August 01, 2001 3:56 AM
To: Tenhave, Tim
Cc: Francesco Lovergine; [email protected]
Subject: Re: [myrinet] RE: Re: Low bandwidth


On Tue, Jul 31, 2001 at 12:51:14PM -0400, Tenhave, Tim wrote:
> Hi,
> 
> I would try moving the Myrinet board into other slots.  I do not have
access
> to an AS500 today, but I do know it contained 2 (or 3) PCI buses and you
may
> be competing for resources from other devices in the bus you are on.  You
> can help yourself determine the nature of your bus by using the SRM "show
> config | more" command and attempt to move your Myrinet board to a quieter
> bus.  Realize the slot numbers provided are logical slots and not physical
> slots.
> 
> If you need more details, send email.
> 
> Tim
> 
> Compaq/DEC Alpha guy who uses Myrinet too.
>   

this is the show config output:



PCI Bus
     Bus 00  Slot 06: DECchip 21040 Network Controller
                                   ewa0.0.0.6.0
00-00-F8-22-F9-E2
 
     Bus 00  Slot 07: Cateyes - 4D40T
     Bus 00  Slot 08: DE500-BA Network Controller
                                   ewb0.0.0.8.0
00-00-F8-10-C9-63
 
     Bus 00  Slot 09: ISP1020 Scsi Controller
                                   pka0.7.0.9.0          SCSI Bus ID 7
                                   dka0.0.0.9.0           RZ29B
                                   dka400.4.0.9.0         RRD45
 
     Bus 00  Slot 10: Intel   8275EB PCI to Eisa Bridge
 
 
     Bus 00  Slot 11: Vendor: 14c1  Device: 8043
     Bus 00  Slot 12: Cateyes - VGA Daughter Card



I could remove the powerstorm graphic card (slots 7/12).
Currently only slot8 is used as fastethernet controller.
Any hints?