What will make a system "hiccup" like this?

[Painman]

This problem relates to my legacy box. It's got an ASUS CUBX, PIII CuMine 700, 512MB (4*128MB) PC100, GF4 Ti4600, SB Live! Value, Linksys LNE100TX NIC, 13 GB WD HDD, an ISA SB16, plain old IBM PS2 104 key and a Logitech LX3 optical hooked up via PS2. It is *not* currently overclocked.

I hadn't used the box in a while, but fired it up again for some old school action. Every 30 seconds on the nose, it freezes for a brief moment.

Now here's the wild part: BOTH of my rigs started doing this. The only thing these 2 boxes had in common at the time were the KB and monitor via an old Belkin PS2 KVM. The KVM became suspect and is currently out of the equation (and the main rig is no longer hiccuping). But the legacy box still is. So it seems that whatever the hell the problem is with the legacy rig, it was able to transmit this through the KVM to another box.

I'm now guessing it's a hardware issue, as the legacy box is doing this even in DOS. But, which hardware? I'm hoping someone here might have run into this before so I'm armed with a bit of information before I rip this machine open and start pulling cards, DIMMs, etc.

 

[ForumMaster]

perhaps a bad powersupply providing unstable voltage. since you say it happens in DOS too, then it obviously has nothing to do with windows. try taking everything that's not essential out. maybe try a different power supply.

 

[Bateluer]

When this occurred with one of my systems a while back, it turned out to be bad chipset drivers. Once they were updated, that issue went away. Doesn't sound like it would be chipset issues with your system though. The KVM switch didn't require any special software be installed, did it? Mine does not and never had any odd hiccups on the systems connected to it.

 

[MichaelD]

Something running in the background? Maybe an old, forgotten program that's trying to get out to the net to update itself? Maybe something broadcasting over the NiC?

 

[Zap]

I had a notebook that would do this... turned out it was overheating and the CPU was throttling at those points.

 

[Painman]

I didn't really suspect PSU due to the regularity of the pauses (it's a relatively new Fortron 300 watter); seems like a PSU issue would be more random.

I went to pure DOS via bootdisk and did a deltree on the entire Windows dir. Pausing is still evident even in this environment.

The KVM never required any special software. It's keyboard aware and responds to 2 taps of the scroll lock key + up arrow/down arrow.

The HSF on the CPU is an Alpha FC-PAL35 with a 60*25mm Sunon bolted onto it. Under ideal conditions it should keep this CPU cool as a cucumber, but maybe it should get a checkup to ensure it's still doing its job.

Thanks for the input folks. I'll double check HSF and PSU first - I didn't really suspect these things, but I shouldn't rule anything out.