Fortunately I'm at sea level (San Diego), but like jji666 I have trouble keeping my Seagate 7200.11 1TB and 1.5TB drives under 45C when busy, and they sit around 39-42 when idle.  I'll also note I have a Western Digital 400GB in there as cache that idles around 28C and doesn't break 35C even when busy.  Ambient temp would be around 72-76F (22-24C).  I have "medium" speed fans on these things and good case ventilation, but there seems to be only so much I can do short of putting high noise, high CFM fans on them, which is just not acceptable where I have my server.

 

If I get ambient down to 65F, the Seagates idle in the low 30s.  That tells me ambient has so much more impact on my temps than anything else... not that one should ignore everything else, but obviously if it's 90F in your computer room no amount of fans are gonna save you.

 

The last time I had a drive failure likely due to heat was the last time I went on vacation in June.  I set the air conditioning not to kick in until 82F but it probably got to around 85F in my computer room... I was guessing what was the most I could get away with about the time oil was around $130/barrel and our energy bills were $180/month for a 1100sq ft condo... heh heh.   I think it was actually a WD drive that died, and when that happened and I opened the case, I had found that a fan had frozen up, contributing to the issue.  I guess I should've thought to check all my fans before going on vacation.   

 

Despite it all, I like Seagate... but I'm really looking forward to the Western Digital 2TB Green drives. (http://lime-technology.com/forum/index.php?topic=3213.0)

 

 

I didn't mean to hijack this thread. 

 

I've got direct fans on all the drives.  The main problem is that all of these 4x3 adapters for the drive bays crowd the drives quite close together and there isn't that much airflow between them even though there is a fan on one end blowing through.  42 degrees is the temp of the hottest drive right now during a parity check when they are all spinning.  While I might add another fan in the back of the case to pull some air out, the case is rather maxed out at the moment. 

 

There have been a number of debates on the relative merits of keeping drives cool, warm, or hot.  Most people here think keeping the drives below 40C is a good idea.

 

Sorry if this sounds really basic, but you need some fans blowing air into the case, and some blowing air out of the case.  I pull air in from the front of the case through the drives, and push air out of the back of the case.  Check your fan directions.  Turning around fans might help.  If you have a big imbalance you will not get the cooling effect you're looking for.

 

Some of the backplanes have tiny fans that aren't going to do move enough air to make any difference.  If this is the case, open the backplanes up as much as possible to airflow, and put some high CFM fans evacuaating air out of the case.  This willl create a vacuum effect and suck air in through openings in the case.  The last step is to tape up case openings so that the majority of the air is being sucked in between your drives.

 

Good luck!