I'm building a new server. Configuration is NetBSD 2.0 with raidframe set 
up for RAID 1 on two identical disks. Box is ASUS P5P800 Intel based MB 
with Celeron D CPU.

dmesg below.

It freezes for short periods from time to time. This started after I added 
two 3C509 based netcards. The problem goes away when I remove one. It 
looks like this when I ping one card from another host:

64 bytes from 10.10.144.22: icmp_seq=6787 ttl=255 time=1.809 ms
64 bytes from 10.10.144.22: icmp_seq=6788 ttl=255 time=1.784 ms
64 bytes from 10.10.144.22: icmp_seq=6789 ttl=255 time=2606.026 ms
64 bytes from 10.10.144.22: icmp_seq=6790 ttl=255 time=1606.939 ms
64 bytes from 10.10.144.22: icmp_seq=6791 ttl=255 time=607.168 ms
64 bytes from 10.10.144.22: icmp_seq=6792 ttl=255 time=1.809 ms
64 bytes from 10.10.144.22: icmp_seq=6793 ttl=255 time=1.817 ms

It's not only the network that freezes, the machine stops responding on 
the console too.

Breaking the kernel into the debugger when it's frozen reveals the 
following backtrace:

cpu_Debugger(7,c06b9c70,c06b9c44,c0b2c9e0,7) at netbsd:cpu_Debugger+0x4
comintr(c0c31c00,7,c06b0010,c03f0030,c06b0010) at netbsd:comintr+0x68a
Xintr_legacy4() at netbsd:Xintr_legacy4+0xa4
--- interrupt ---
gettick(2,6,c06b9cf4,c0197138,1) at netbsd:gettick+0x1c
i8254_delay(1,7,0,c048beac,166) at netbsd:i8254_delay+0x17
mii_bitbang_sync(c0c02000,c048beac,0,5,c06b9d34) at netbsd:mii_bitbang_sync+0x4c
mii_bitbang_readreg(c0c02000,c048beac,18,0,c0c04068) at netbsd:mii_bitbang_readreg+0x1d
ex_mii_readreg(c0c02000,18,0,bf7,c0c02000) at netbsd:ex_mii_readreg+0x49
nsphy_reset(c0bcf700,18,1,c0b2cba0,170d000) at netbsd:nsphy_reset+0x53
mii_phy_tick(c0bcf700,38,c0bc0590,c0bc0554,20) at netbsd:mii_phy_tick+0x80
nsphy_service(c0bcf700,c0c04068,1,c0c04068,c0c02000) at netbsd:nsphy_service+0x6a
mii_tick(c0c04068,1,c03f33ec,c0bc0500,c0c02000) at netbsd:mii_tick+0x1a
ex_tick(c0c02000,c06b9e50,c0b2c9e0,0,c06b9e7c) at netbsd:ex_tick+0xbb
softclock(0,c06b9e70,c03fd9e1,c06b9e7c,c0126f49) at netbsd:softclock+0x259
softintr_dispatch(0,e580010,70030,a7460010,10) at netbsd:softintr_dispatch+0x73
Xsoftclock() at netbsd:Xsoftclock+0x25

vmstat shows that the cpu load is 40% system, 60% idle (exact figures).

What could be going on here? Can't these cards coexist?

Cheers,
- Anders