Re: [myrinet] Re: Question on max sizes

OK, I'll take a stab as well.

The Myrinet tutorial[1] (which is linked from the Myricom website) says
that the switches and cards will timeout if a tail flit is not seen within
a timeout period.  On the cards (lanai 4) this can be set to a max of 4
seconds, and on the switches it can be between 4 and 1/16 seconds,
depending on the switch.  When the card times-out, the NRES signal is set,
when the switch times-out, a tail flit is sent.  This limits the maximum
message size.

[1] James Otto, The Myrinet Tutorial.  Available at
    http://www.cs.unm.edu/~jotto/myri/myri.html

Darius

On Thu, 18 Jan 2001, Douglas Johnson wrote:

> Since I haven't seen an answer to your question, I'll take a stab at it
> (hopefully not incorrect). The max message size is 2^31-1 if your os
> supports that much dma'able memory.
> 
> Doug
> 
> On Mon, 15 Jan 2001, Davis, Harvey wrote:
> 
> > Hello
> > 
> > I was just wondering if there is a limit to the maximum amount of data that
> > you can send in one hit across the myrinet.
> > 
> > Any limit (non-physical) on the amount of DMA that can be contigously
> > allocated?
> > 
> > Thankyou for you help
> > 
> > Harvey Davis
> > Australian Department of Defence
> > 
> 
>