Have my rig almost complete, is running and making minor tweaks to cooling. Taking off the side of the case the MB temp (measured at the southbridge heatsink) drops from mid 54C to 46C at idle. See pic.
The Southbridge heatsink at the RED square is where I need air.
I'm thinking if I mount a quiet 800RPM 120mm fan in the white circle, it will take the incoming air from the front of the case and redirect that air onto the SB. Any opinions on this idea? TIA
http://mysite.verizon.net/fibre/PC/Dscn0927a.jpg

Is it stable? You can replace the heatsink but southbridges do not ussually get very hot. Probably does not need another fan in there. Don't worry about the temps of the southbridge as long as everything is stable.

I have P180 with Asus P5B. When I put an extra fan in the upper hard-drive cage, it reduces my SB temp by about 6 C. However I cannot mount any hard-drive in that cage anymore.

Yeah i had that problem but if your gfx card is 10.5" just remove the lower hard drive bay and mount a fan inside the case. That 120mm fan will suck cold air from out side and blow it directly into the gfx intake as well as blowing cold air directly over the southbridge. You should go to the bios and set the Southbridge voltage to the lowest voltage setting available. Also if your northbridge voltage is set to auto, it will be unnecessarily high. You can achieve stability at 1.2V @ 4ghz with the x58. I'm sure you could go lower say 1.875V might be the sweet spot for 4ghz on the northbridge.
As for the upper hard drive bay, Install the hard drive bay up top. Remove the upper flip open white door and filter. First thing you will want to do is find the metal hole that is just the right size to squeeze your 3-pin power connector through, pull it all the way through. Now zip tie the top left and bottom right fan holes into the fan holes. At this point you will have superior cooling for the northbridge and southbridge. Antec made some serious designs flaws on this case that drive me crazy! otherwise it's the best cooling microatx case for Core i7 X58 systems. Antec should have made the case longer so u can install a 10.5" graphics card and still keep the hard drive cage in there. Also they should have designed it correctly as to be able to mount fans both on the top and bottom of the front of the case with the cages installed. Anyway i scrapped the case because i couldn't install enough hard drives, now everything in my system is running way hotter! I'm going to custom build a case using a $20 rosewill case on newegg, custom mount a hard drive cage that will hold 6 hard drives and engineer it to fit the 10.5" graphics card with sufficient cooling that should/ will exceed the antec p180's cooling design. Good Luck!!!

later dude

you could have easily installed 7 hard drives in the p18x, without using the upper hd cage, by putting a bay converter in the top bay... bay converters have 120mm fan mounts as well, so there would have been plenty of air.

southbridge temps are not an issue, but for the paranoid, your suggestion to tweak the voltage is a good idea.

Regarding southbridge temps. That's exactly what i thought before i bought an x58 board running a 1366 socket cpu. The northbridge and southbridge run the same temps without sufficient airflow. Idling roughly around 60-65 Degrees Celsius. More under load. I have like 5 120mm fans in this poorly designed NZXT Gamma Classic case. If you read the intel technical articles in regards to the x58 chipset and ICH10R should never exceed 55 degrees for longer life. cya.

This is good info on to what measures will be required to attempt to meet the manufacturer cooling tdp specifications while overclocking/ over voltage the Northbridge. With a high 35 degrees Celsius ambient temperature the stock IOH x58 chipset should not exceed 56 degrees Celsius under a 13W load which can translate into chipset voltage.

By the way 'danimal' that's a good idea about coverting the 5.25 inch bay(s) with the fan to cool the hard drives. Thanks.

you'll get rid of that mb long before the southbridge dies, but you could always try replacing the thermal paste in the meantime, see if it makes a difference.

this will add some air over that chip:

http://www.scythe-eu.com/en/products/pc ... -stay.html

Remove the cover over the heatsink, it helps a bit.

other than that, the SB will handle <60C without a problem, leave it be

I re did my cooling config and now the sb runs 35 under load and the northbridge is at 44 degrees under 100% load stress test on everest ultimate. I did a 5 second lap to the core i7 930 as to barely tell in attempt to keep my warranty. I also lapped my Cocage True Spirit from 400 grit to 2000 grit. I used IC Diamond 24 carat thermal paste why is the pastiest driest, most pain to apply thermal paste i've used. Arctic silver 5 was much easier to spread. Only difference is after doing all that i'm barely breaking 70 degree celsius under load. Before i hit 85 plus on this cooler with this overclock. I am pretty anal about my temps so i'm really happy. The only concern i have is, more core #1 is the hottest, the cores getter hotter from #4 and up. #4 being the coolest, and #1 being the hottest. Are there specific bios settings that can cause this? Like Core Level or Clock Skew?

unfortunately you can't control the individual core temps... i lapped my i7-920 pretty hard, and i still have a spread of nearly 10 degrees sometimes.

you can calibrate the realtemp software on the high end, which is supposed to make up some of those differences, but i haven't seen it yet.