Dell GX270 hot northbridge, southbridge

[larrymoencurly]

I'm measuring over 75C for the north bridge and south bridge (Intel 845G chipset, 2.8 GHz Pentium 4) of a Dell Optiplex GX270, and this is hot enough to make the computer become sluggish and make YouTube videos jerky (low resolution, 360-480 lines max). On a different GX270, also with a 2.8 GHz Pentium 4, those chips run 30C cooler.

[BigTroll]

Re: Dell GX270 hot northbridge, southbridge

I work on a ton of these at my school, we have thrown out 30 of them, some gx270s i noticed had a prescott pentium 4 and they run alot hotter, I think another tech may have added them, either way cap failures have put most out to pasture, usually bad nichicon or rubycons, i even found a refurb board with SU'SCONS and funny none of the cpu caps were bloated but the southbridge died. and yeah they suck at youtube no matter what, no h.264 decode and it rapes the cpu.

[Pentium4]

Re: Dell GX270 hot northbridge, southbridge

Maybe that ones PSU is outputting higher voltages? If you don't have a video card I'd imagine it'd be sluggish watching youtube videos no matter what

[momaka]

Re: Dell GX270 hot northbridge, southbridge

Is this the SFF or normal size desktop tower version? Are you sure these don't use the i865 chipset? I have a GX270 motherboard from the tower version, and my chipset tends to run quite hot too (though nowhere near 75C since the CPU heat sink I have installed blows air on the chipset heat sink as well.

I think you may want to check the chipset filter capacitor. A friend of mine brought me one to fix. It had a blown Rubycon MCZ filter cap on the chipset supply. Apparently, the MOSFET next to it runs really really hot. I installed a large 10x20 Panasonic FL cap in place of that and got my friend's GX270 running line new again.


As far as the jerky YouTube videos:

- Q1: Is the CPU getting adequate cooling? Check the heat sink - it should be all copper. I believe the GX240 or GX260 had all-aluminum heat sinks that were the same size and interchangeable. Make sure someone didn't swap it. If you have an all-aluminum, that won't be enough to cool down those hot P4s, especially the Prescotts.

- Q2: Does the CPU have hyper-threading (HT) and is it enabled in BIOS. I find that HT helps A LOT on Pentium 4 processors when it comes to processing flash content. I can watch 720p videos on YouTube with my 2.8 GHz Pentium 4 (Dell Optiplex 170L) without any jerkyness when HT is enabled.

[Uranium-235]

Re: Dell GX270 hot northbridge, southbridge

I work on a ton of these at my school, we have thrown out 30 of them, some gx270s i noticed had a prescott pentium 4 and they run alot hotter, I think another tech may have added them, either way cap failures have put most out to pasture, usually bad nichicon or rubycons, i even found a refurb board with SU'SCONS and funny none of the cpu caps were bloated but the southbridge died. and yeah they suck at youtube no matter what, no h.264 decode and it rapes the cpu.

prescotts have heat problems. I had to lower the voltage below range on my P4 shuttle for a 3.2 prescott, and that fucker still can get 80C under prime 95 give it long enough. I polyd the CPU vrm, but boy those mosfets get hot too

[Pentium4]

Re: Dell GX270 hot northbridge, southbridge

That's hot...good thing prime 95 isn't realistic for normal applications especially if it's for a HTPC. Although if you use netflix, stupid silverlight bogs down the CPU so much

[Uranium-235]

Re: Dell GX270 hot northbridge, southbridge

its not an HTPC. I have a C2D 6750 on a Silverstone microatx short desktop for that

its for a portable PC to let customers borrow if they have a dead pc/laptop

[larrymoencurly]

Re: Dell GX270 hot northbridge, southbridge

These GX270s have mostly Rubycons around the CPU, and I replaced the Nichicons elsewhere on all the boards long ago. All the 2.8 GHz CPUs are Northwoods with aluminum-only heatsinks, and I've run them with hyperthreading enabled and disabled.

I should have mentioned that the sluggishness with this one GX270 doesn't start until its north bridge and south bridge become a lot hotter than those chips on the other mobos. I tried it with two different PSUs, the stock Dell HiPro (in the case) and a recapped Antec SmartPower (outside the case). All my GX270s have aluminum heatsinks, some originally with grey paste (including the sluggish one), others with a dry foil thermal pad. I switched them all to regular white silicone transistor grease. I've also swapped CPUs between mobos, but that didn't change anything.