Ive got an external hdd in an aluminium case with its own power supply and i wanted to keep it a bit cooler and i was wondering if i could piggy-back a molex fan off the power supply to the hdd?... i dont want to be overloading the supply to the hdd though. would this work? if not.. any suggestions? thanks.
i don't see why not. check the Max Ampere draw on the fan and add 500mA to 750mA to take into account of an aging or dusty fan. Add that number to the HDD spec at the vendor website. my feeling is the power adapter should have enough juice, but these things are probably made in china ~~ anything can happen if the total Amp draw is less than 70% - 80% of what is specified on the adapter, i think it should be ok for long term use.
most external power supplies provided with caddies put out between 1.5 and 2A, so you should be fine.
Unlike most PC components harddrives are less effected by heat. And in the main, there's is absolutely no reason to 'cool' a harddrive as there are no benefits to be made from doing so. There has been a lot of research done by harddrive manufactures & 3rd parties to prove this to be true. http://209.85.163.132/papers/disk_failures.pdf As a general rule, as long as the harddrive is not being saturated by an external heat source or thermally insulated, then the heat that it produces by itself is fine.
Great link. Yeah, i read that a couple times. Page 6. Figure 5. Before catastrophic failure , there are higher probability of bad sectors appearing with higher temperature environment. Higher temp has a way of whacking the firmware as well. The question is how high and sustained for how long. That's in the paper. My Data (musics, digital photos, projects documents and software codes) are a more valuable than all my PC hardware combined.
It's just a rule of thumb, but I'm sure most people will agree that as long as you keep your drives below 50 / 55c you won't have a problem. I wouldn't say you'll get that heat in a ali case, but then I've seen them with 40mm fans, and I suppose they're there for a reason.
I used to have 2 drives right on top of each other, with no airflow over them. and only the psu providing airflow out of the case. I still have the same drives, they are 60 and 80gb. both were about 200cdn when new and were considered higher end at the time so that tells you how old they are. I thought they were fine, one day I just happened to touch one of them. it damm near burned me! both drives still work, one is starting to get cranky. but I think thats because it only had 1gb left on it. anyway, both are a few years old and still work despite being cooked for about a year. as long as the drive isn't hot to the touch, it should be fine as per my experince.
hmm, that paper is interesting.. thanks for that. its hard to tell what temp its at.. i cant find a hdd temperature monitor that is compatible with a USB connected drive... when i put my hand on it.... and then think of how hot a 45'C day is... i cant help but think its at about 55-60'C constantly... ill look into the current draw.... thanks for that info also. i was wondering.... if i put the fan on the bottom of the drive directly, i would need to leave half the case off.... would this expose it to too much dust and humidty... im thinking it would be close to the amount it would be exposed to inside a case anyway. Thanks everyone
ah, i found the specs for my HDD: Spin Up Current (max.) 650 / 1900 mA... so would i have to use the 1900 value? that would suck because these are the amperage output specs of the case: Output: Dual DC +5V 2A / +12V 2A.... what do they mean by a dual output? is it 4A but in different voltages? or is is 2A in either 5V or 12V?
I'm going to put in a guess that there are four pins coming from the powersupply to run the hard disk - so 2 will give 5v at 2A and the other 2 will get 12v at 2A. That's presumably so they can provide a molex connection to the drive. I'm not completely sure what you mean about leaving the case open - but hard disks are usually behind open fans and get covered in dust. They're sealed (sometimes there's a valve to equal pressure through a tiny hole on the top), so dust isn't a problem.
Ahh, ok. Because the spin-up current for my HDD is 1.9A... and the enclosure only provides 2A... should i look for a fan with a switch and only turn it on after the HDD has spun up? . Can't find one with a switch.... what kind of switch would i need to wire in myself?
anything really. depends on what you want it to look like. as long as it can open and close the circuit.
