Refining my case cooling - A few questions

[RyanM]

After 3 years of running essentially the same cooling setup, I've decided it's time to switch things up a bit. I just upgrade to an Athlon XP processor, and I'm not happy with the temperature it's running at. By no means is it spontaneously combusting, but nonetheless, I'd like to get it down to a more reasonable temperature should I want to play around with some simple overclocks.

I'm currently engineering a fan setup so that the amount of air coming in from the front of the case roughly equals the amount of air leaving the case through the rear. I've managed to work out a fan configuration to do just that, and I should be able to theoretically pump and evacuate around 140 CFM.

The questions I have are this:

Which side of the harddrive benefits the most from heat dissipation? The circuit side, or the top side? I plan on rigging up some low-profile heatsinks, and making sure the hard drives recieve about 16 CFM apiece, but I'm not sure which side to focus the flow on.

Also, are there any hard drive cooling kits on the market that do NOT include the fans alreaday? I'm simply looking for a ready-made HDD heatsink that I can plop on there to increase cooling from bay coolers I already have mounted. I'd rather not spend the extra money and end up with more spare bay coolers than I know what to do with.

Finally, I was planning on making most of my purchases through NewEgg and Nexfan, but I was wondering if anyone had any other favorite sites that might perhaps offer more competitive pricing and service.

Thanks in advance,

Mach

 

[RyanM]

Also, I'm looking for a fan adapter for my CPU heatsink that'll convert from 60mm to 90/92mm. Newegg's model is out of stock, and I am having trouble locating them elsewhere.

Also, does anyone have any experience with these? I just don't want to apply too much pressure to the socket. The heatsink I'm planning on getting is a 3-prong one, so it'll be sturdily mounted.

 

[BG4533]

Heatsinks for HDs are pretty pointless. They would have to be attached very tight and epoxied on to make any difference and even then it probably would be small. HDs generally can handle up to 55c. Even in an mostly enclosed area, without a fan, mine didnt get that hot. With an 18cfm fan blowing across my IBM 60GXP it is at 28c, more than cool enough.

A 60 to 92mm adapter? To put a 92mm fan on a 60mm heatsink? These are very restrictive and would provide little performance increase for the money. If you are still using a 60mm heatsink, you should get an 80mm one. If money is very tight a GC68 from SVC is only $4.99 would be almost definitely better than a 60mm unit. If you are planning on putting a 60mm fan on a 92mm heatsink, just get a 80mm fan. Much quieter for lots more airflow.

Brian

 

[RyanM]

For my CPU, money isn't really the issue. Sound level and CFM's are what I'm looking at. I'm trying to planning on mounting a 92mm fan on a 60mm heatsink. I could easily go with one of those 80mm fans and adapters, but I'd only be pushing around 45 CFM and I'd suffer through decibel levels in the 40's. With a 92mm fan, I'll be pushing 56.8 CFM, minus the restriction of the adapter, plus I'll only be putting out 35 decibels. To me, that makes a lot more sense.

Thanks for the heads up on the hard drive heatsinks. I'll probably just stick with my bay cooler solution then. Nonetheless, the way the hard drives are mounted, the tops of them are most exposed to the airflow. Is this the part that's preferred to be cooled, or should I flip them upside down give the circuit side the benefit of the airflow?

 

[BG4533]

I think you would gain much better performance with an 80mm heatsink. You can get 80mm fans that put out ~45cfm at 33.5dB. If you are overclocking the XP1800 in your profile, for a few hundred megahertz you would only need a good 80mm heatsink and maybe 30 or so CFM. Something like a Panaflo H1A (39.6CFM, 32db) and Thermalright SK-7 or SLK-800 would likely mop the floor with most all 60mm heatsinks and 92mm fans. Most people say that the restriction of a 92mm fan on a 80mm heatsink is too much. If that is the case, I think the 92 on a 60 would really be bad.

As for the hard drives, I really dont know what puts out more heat. Maybe consider running them without a fan to test and see which side feels warmer. Then go from there. I currently have a fan that blows across the whole drive, so i have never thought about it much.

Brian

 

[RyanM]

See, that's the thing. That 80mm fan sure is nice, and relatively quiet, but it's only 40 CFM. I have a 60mm fan on my stock heatsink that pushes 42 CFM, and yeah it's kinda loud, but I'd then be going BACKWARDS in my ability to push air onto the heatsink. Given, it'd be a much better heatsink, but nonetheless, I don't wanna stand still.

I don't understand what these people are talking about by restriction. Yes, a 92mm to 60mm converter will cut down the surface area that the fan is projecting at, but it's also funneling the air simultaneously. Though there's gonna be some restriction, there will also be an increase in the velocity of the air traveling through the sink. The efficiency of the fan may be reduced by 10%, but 10% off of 57 CFM is still a good 25% more air than a 80mm fan.

 

[OulOat]

Originally posted by: MachFive
See, that's the thing. That 80mm fan sure is nice, and relatively quiet, but it's only 40 CFM. I have a 60mm fan on my stock heatsink that pushes 42 CFM, and yeah it's kinda loud, but I'd then be going BACKWARDS in my ability to push air onto the heatsink. Given, it'd be a much better heatsink, but nonetheless, I don't wanna stand still.

I don't understand what these people are talking about by restriction. Yes, a 92mm to 60mm converter will cut down the surface area that the fan is projecting at, but it's also funneling the air simultaneously. Though there's gonna be some restriction, there will also be an increase in the velocity of the air traveling through the sink. The efficiency of the fan may be reduced by 10%, but 10% off of 57 CFM is still a good 25% more air than a 80mm fan.

It's not going to be 10% though. It's going to be a lot more. By going from 92 to 60 you are decreasing the area by 57%. That equals a lot of back pressure which will reduce the airflow greatly and increase noise too. Sure, the air exiting will be faster, but still not as efficent as an plain old 80mm. Also, you are not considering that 80mm hs will have a greater surface area than that 60mm. I can't give an exact number, since that depends on the hs, but it will be a big increase. That is what so great about 80 hsfs, you don't need to move as much air as a 60mm to obtain better cooling.

 

[RyanM]

Well, I'm currently looking at HS in the $25 range. I can pick up a Akasa Silver Mountain II for that, and it's seen some damn good reviews. I really dig the silver coating as well.

What would you recommend for an all-copper, 60mm on the bottom, 80mm on the top heatsink, that costs less than 30 dollars but'll do as good a job as the Akasa?

 

[BG4533]

Thermalright SK7. Great cooler for the money. Only $20 at SVC, but it is currently OOS. Then, go with an 80mm fan that fits your needs. Something like the Y.S. Tech adjustable fans might be good for you as they would allow you to adjust the fan speed between performance and noise.

Brian