Recent AMD760MPX chipset PCI measurements??

Patrick Geoffray patrick at
Tue Feb 19 01:00:39 PST 2002

Hello Luc,

Luc Renambot wrote:
> Nice point. Do you know if it's also true on the AMD-760 MP Chipset ?

Nope, I have never had the curiosity to check that on a MP. Anyone on 
the list with a 760 MP to run "/sbin/lspci -tv" ?

> We have built here a small cluster for parallel rendering (9 dual-athlon
> 1500+ and GeForce3, inter-connected with old Myrinet card for now).
> We were thinking of doing pixels transfer from the graphics card to
> Myrinet, since it's possible on the Nvidia cards to allocate data
> either on AGP or video memory. Do you have any ideas/pointers about
> that ?

That should be easy. The support has been added to GM-1.5.1: you just 
need to mmap the PCI/AGP memory into user space, and then gm_register 
the segment. You can then send/recv from/to this piece of memory. It 
should even be possible to send/recv with MPICH-GM when the PCI space is 
mapped in user space. Note that it's only supported on x86, as there is 
holes in the address space on Alpha and IA64.


|   Patrick Geoffray, Ph.D.      patrick at
|   Myricom, Inc.      
|   Cell:  865-389-8852          685 Emory Valley Rd (B)
|   Phone: 865-425-0978          Oak Ridge, TN 37830

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