0Stability issues

I’ve been hav­ing some sta­bil­ity issues with my HTPC recently. A rein­stall did­n’t help so I con­cluded it was hard­ware. Remov­ing all non essen­tials did­n’t help either so I figured it must be CPU, memory or mobo related. Noth­ing is over­clocked or tweaked and its all fairly recent brand name kit. I stress tested the CPU and memory without caus­ing either to fail, but I con­tin­ued to get occa­sion­al lockups and inter­mit­tent slug­gish performance.

Now because this is a htpc, it is in a smallish case with low air­flow. It has 2 120mm fans but they’re con­trolled based on CPU temp and are usu­ally off due to low CPU usage com­bined with the huge Scythe Ninja heat­sink. I knew the CPU was­n’t over­heat­ing but thought i’d check the gpu (A pass­ive Radeon 5450) and hdd, which is in a sus­pen­sion mount­ing which reduces the cool­ing it receives.

How­ever both hdd and gpu were barely luke­warm. In the pro­cess I happened to catch my hand on the fairly sub­stan­tial chip­set heat­sink (labelled “giga­byte” in the photo below). Ouch! I had­n’t real­ised that even with the sub­stan­tial cool­er the chip­set required or expec­ted some act­ive cool­ing from the nearby CPU sock­et. I don’t have a fan dir­ectly on the CPU heat­sink (as you can see below) and the air­flow over the chip­set clearly was­n’t suf­fi­cient. Ori­gin­ally I had the fans arranged blow­ing air out of the case, but decided to try a small rearrange­ment — revers­ing them and frac­tion­ally increas­ing their min­im­um speed. Pos­it­ive case pres­sure is gen­er­ally good prac­tice any­way, and this way air is forced past the heat­sink to exit the case. This small change seems to have done the trick.
Mor­al of the story: some recent(ish) chip­sets (e.g. Intel series 4 chip­sets) require reas­on­able air­flow (or a heat­sink upgrade — e.g. the Thermal­right HR-05 which is now on my shop­ping list).  It may also be a good idea to upgrade the thermal goop sup­plied with a high qual­ity com­pound. I recom­mend IC 7 Dia­mond if you can’t.
One final note — in my case the com­pan­ion south­bridge, with a tiny “heat­sink”, (cen­ter bot­tom of image) was only medi­um-warm and clearly does­n’t require any changes.