I just got some surprising performance numbers. I have three systems, call them A, B and C. A is a file server, B is supposed to be a fast server and C is my desktop. I'm trying to improve the performance of a job that normally runs on B and manipulates files on A, so I wrote a little test program. I ran it on all three machines. My test creates 10000 symlinks to a file. Symlinks and the file are accessed via NFS from A. It was fastest on A (less than 1 second) - no surprise using local disk. It took 5 seconds on C. It took 23 seconds on B! Big surprise. Anybody have any thoughts on what makes B so slow? All are connected to each other through a gigabit switch. In addition, A and B have additional gigabit NICS connected directly to each other. Here are some system details: A: Tyan S5350 Tiger i7320 dual 2.8 GHz Xeon, 1 GB memory, lots of SATA disks with 3ware controllers. SUSE 9.2 Intel PRO/1000 MT Dual Port NIC - quiescent during tests Intel PRO/1000 MT Dual Port NIC - direct connect to B Broadcom NetXtreme BCM5721 Gigabit NIC PCI Express - unused Broadcom NetXtreme BCM5721 Gigabit NIC PCI Express - main network B: Tyan S2882 Thunder K8S pro, dual Opteron 242, 8 GB memory, fast SCSI local disks, SUSE 9.2 Intel EtherExpress PRO/100 S Server Adapter - unused. Broadcom NetXtreme BCM5704 Gigabit NIC - direct connect to A. Broadcom NetXtreme BCM5704 Gigabit NIC - main network. C: Intel D925 / P4-3600, 2 GB memory, SATA local disk, SUSE 9.3, Intel 82547EI Gigabit NIC - main network While the test is running, 'vmstat 1' on B shows lines like: procs -----------memory------------ -swap --io- --system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 30716 2616544 42620 4389496 0 0 0 0 5698 4616 0 5 95 0 while on C it shows: 1 0 23820 737800 322640 372736 0 0 0 0 9311 12258 1 7 93 0 So C is managing nearly twice as many interrupts and three times as many context switches per second as B. On quiet systems, nttcp shows very similar transmit (910 Mbps) rates from both B and C to A. The receive rate to C (930 Mbps) is a bit better than to B (840 Mbps). But I don't think there's anything wrong with the basic network. Any ideas on how to improve B's performance would be very welcome. Thanks, Dave