[mpich-discuss] Scalability of Intel quad core (Harpertown) cluster

[Scott Atchley]

Hi Hee Il,

If you do not have any machines with Myri-10G NICs (Myricom 10 Gb/s  
NICs), they you can ignore interoperability. :-)

Scott

On Mar 31, 2008, at 3:39 PM, Hee Il Kim wrote:
> Thanks Scott,
>
> I'm eager to try Open-MX. I'm using Netgear GSM7224 switch which  
> supports flow control ( IEEE 802.3x Flow Control) and jumbo frame.  
> I don't understand the interoperability. I assume it doesn't  
> require at the moment.
>
> Hee Il
>
> 2008/3/31, Scott Atchley <atchley at myri.com>: On Mar 28, 2008, at  
> 1:50 AM, Hee Il Kim wrote:
>
> > - If the gigabit network was the cause, could it be improved with
> > Open-MX?
>
>
> Hi Kim,
>
> Depending on your Ethernet switch, Open-MX should be able to lower
> your latency and reduce your CPU usage. I see about 10.5 us
> internally using the e1000 driver with interrupt coalescing turned
> off, others report that they have seen as low as 6.5 us (I do not
> know what NICs they used or if it the machines were switched or back-
> to-back).
>
> To use Open-MX, your switch must support flow control for send and
> receive (some don't) and jumbo frames. If you need interoperability
> with native MX over Ethernet (some hosts with Myri-10G NICs connected
> to an Ethernet switch, some hosts with non-Myricom NICs), then your
> switch must handle at least 4 KB frames. If you do not need
> interoperability, then you can use 8 or 9 KB frames and possibly see
> slightly better performance (fewer interrupts).
>
> Brice released version 0.4.0 which has working interoperability with
> native MX and is nearly feature complete. See http://www.open-mx.org
> for the status and source code.
>
>
> Scott
>
>