Query about fans and mobo power

Slugbait · Post by **Slugbait** » Sat Jan 18, 2003 3:45 pm

I've got an Asus P4B533 running a 1.6A Northwood with retail HSF. The mobo has three fan connectors, one each for the CPU, PSU and chassis.

According to my mobo manual, the fan connectors support cooling fans of 350mA~740mA (8.88W max) or a total of 1A~2.22A (26.64W max) at +12V. And that's where my confusion initially begins...this is greek to me. Anyway...

On the chassis fan connector, I have one-half of my card cooler plugged in. In order to plug in the other half of this fan system, and allow mobo-monitoring of fan speeds, I will need to buy this 3-pin y-adapter. However, I don't know whether or not that will go over my power limit...currently, the card cooler is using two watts, and hooking up the y-adapter (and thus activating the second fan) will suck 4 watts.

I have an Enermax EG365P-VE(FC), and the 3-pin is connected to the PWRFAN connector. I believe this is only for fan speed monitoring, and doesn't actually suck any wattage. But I can't find any info to verify this...anybody know? If so, how much?

I also couldn't find info on how much wattage my HSF is sucking.

Here's my hope: I would like to be able to hook up the y-adapter for the card cooler, plus upgrade my HSF to
this Zalman unit. My ultimate goal is to go from 2.24G to 2.4G, but with my current config, the box is a bit unstable at 2.4G. I figure with the addition of the card cooler, plus a better air-flow system that the Zalman would provide, will allow me this luxury.

But I don't know if it would suck too much wattage.

blade · Post by **blade** » Sat Jan 18, 2003 5:12 pm

I believe this is only for fan speed monitoring

That is correct.

As for connecting the card cooler to the mobo, why not just plug it in to a 4 pin connector from the power supply. I've never trusted connecting too many things to those mobo connectors. Plus I have seen where some burned them out. Is monitoring the fan's rpm that important. Better safe than sorry anyway.

That zalman cooler is a horse. I have one here now that will be given away in our next contest. But with it you'll need it pointing to an exhaust fan to maintain it's effeciency.

Slugbait · Post by **Slugbait** » Sat Jan 18, 2003 8:27 pm

I would prefer the fans make more noise only when under intense usage like UT2K3, and then slow down and be quieter when I'm simply surfing or doing webwork or whatever (plus, I run my box 24/7). Using molar means full speed at all times. And I do plan to overclock my Ti200, hopefully to Ti500 speeds. Just don't wanna do it until I get both fans operational. The bonus is that the card cooler is so big, it also cools my Voodoo5

About exhaust, yeah, the Zalman would point directly to my PSU intake fan, and as I understand, the less heat in the box = the slower the PSU fans will spin, and again lower my noise level even further. I have an Inwin Q500 tower, so large vents on the side of the case at the bottom allow the card cooler to easily suck the air inward. But then, the stock HSF also pushes inward. And I also have a chassis fan on the front pushing in, so while vents at the top allow some heat to escape and the PSU dual-fan sucks a lot out, I'm suspecting that there is still too much "stagnant" heat swirling around my innards. So I figure if the Zalman is sucking instead of blowing, and redirecting the air to an exit...

So quieter fans during non-intensive usage is why I'm concerned about wattage, and whether or not the Zalman is going to put me over the top, etc.

blade · Post by **blade** » Mon Jan 20, 2003 7:27 pm

the Zalman would point directly to my PSU intake fan, and as I understand

On the back of the packaging of the one I have it shows an illustration pointing the duct towards a rear exhaust fan instead of the power supply intake fan. You prefer quiet then for sure point that duct towards a rear exhaust fan. If directed towards the ps intake fan then that means more heat going in and louder fans. That is if the Enermax you have is temp controlled?

Zalman heatsinks are meant as a "quiet" cooling solution, not for performance. I've done some moderate oc'ing with them but for any heavy oc'ing they won't do the job.

Slugbait · Post by **Slugbait** » Mon Jan 20, 2003 9:18 pm

Well, I went ahead and connected the second fan on the card cooler directly to the PSU. There's a fair amount of air running over the top of my video card, too...right toward the CPU.

So just for chuckles, I clocked up to 2.4G, closed the case, and low-n-behold...Prime95 was still going after a half-hour (it quit within a minute or so last time I tried 2.4G, without the card cooler, and Prime95 would only run if I was at 2.24G).

System has been running for more than a day, doing light duties...will install UT2K3 tomorrow, see how it performs. And it's really not that loud with those additional fans that I can hear, maybe I was just anxious to spend mo' money, buy cool stuff, crack my case, etc...