Hi, managers:
We have some performance problem using PVM in our Alpha, DU4.0d based
environment. Would appreciate your input on this issue.
Our parallel application code, using PVM message passing, runs well
over 30 SUN workstations connected by fast ethernet. On a single 4100,
with PVM_ARCH=ALPHAMP, we can also get a 4-fold speed up. But, over multiple
Alpha stations connected by dedicated fast ethernet/FDDI, the PVM code
performs poorly. Monitor showed excessive system call and system wait,
low percentage user time.
I have run some simple node-to-node communication test which pingpongs
long (>10K words) messages back and forth. I can only get 3 MByte/sec
rate over the 100Mb ethernet. I tried to increase the system parameter
tcp_sendspace=65536 and tcp_recvspace=65536, but it does not help.
Here are my questions:
1. If PVM works in your environment, is its performance on Alpha stations
any worse than other workstations? Have you tuned the system parameters
to make it work?
2. Digital has its own version of PVM, but it requires TrueCluster software
and "Standard network interconnects are not supported." In your experience,
is it worthy of the trouble to get and install Digital's PVM?
Thanks in advance for your helps.
llliu_at_netscape.net
Received on Thu Mar 18 1999 - 18:30:45 NZDT