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Open-fan GPU or fan-blower GPU?

PowerMac G4 MDD

PowerMac G4 MDD

macrumors 68000
Original poster
Jul 13, 2014
1,900
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I got a 5770 (flashed) for my 1,1 Mac Pro, and the thing's fan seems to be worn out or something, as it's extremely loud and sounds like a motor. Under normal circumstances, I would expect these to be silent...

But are they really? How does one compared to an open-blade style GPU? We're talking about a 2009 GPU, so note that the newest fan-blowers are likely way quieter.

I have the option of getting either an open-fan 5770 or a fan-blower 5770. Which would be best?

Hopefully the open-fan design is quiet enough, as the Mac Pro has great airflow; a fan-blower is more appropriate for a small, enclosed case--if I'm correct.

-Thanks
 
Personally, I prefer GPU coolers to exhaust the heat from the GPU out of the Mac Pro. This will help keep other components in the Mac Pro cooler. This would be especially beneficial to those who have upgraded their Mac Pros to 130W CPUs and probably lead to the Mac Pro's expansion slot fan to ramp up less frequently and to a lower RPM.

When I switch graphics cards from one with open fan type cooler to one with blower type, I saw an immediate reduction in temps on my Northbridge. I'm not sure about other components (forgot to take notice), but I would believe that they shared the same reductions in temps.
 
In general, the fan type cooler is quieter than the blower type, especially under load. However, it's not always true, a poor fan can be very noisy, and a good blower can stay quiet. I recently get this card, which is a blower type, but very quiet even under full load. The PCIe fan is definitely louder than the card itself.
h280qc3g2m_04_1600-jpg.569494


Also, I won't consider there is a great airflow in the cMP (for fan type PCIe card). Technically, the hot air has no way out due the the back of the slot is a dead end, and there is no other fan work like the CPU cage extract fan to actively pull the hot air out. Remember, hot air rise, that means you have to wait until the hot air is filled up the whole case, then the extract fan at the bottom can pull the hot air out. IMO, this is a very ineffective way to clear the hot air. Unless you remove all the little metal protector from the PCIe slot, and place you Mac Pro in this orientation. Then all the hot air will able to get out easily to let the machine stay cool.
macpro2-1-jpg.487324
 
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When I changed my Apple 5870 to an open 7950, the PCIe bay fan had to do a lot more work and was very audible. I did find the GPU stayed much cooler with a proper open fan cooler but at the expense of extra PCIe fan noise.
 
h9826790 said:
In general, the fan type cooler is quieter than the blower type, especially under load. However, it's not always true, a poor fan can be very noisy, and a good blower can stay quiet. I recently get this card, which is a blower type, but very quiet even under full load. The PCIe fan is definitely louder than the card itself.
h280qc3g2m_04_1600-jpg.569494


Also, I won't consider there is a great airflow in the cMP (for the PCIe card). Technically, the hot air has no way out due the the back of the slot is a dead end, and there is no other fan work like the CPU cage extract fan to actively pull the hot air out. Remember, hot air rise, that means you have to wait until the hot air is filled up the whole case, then the extract fan at the bottom can pull the hot air out. IMO, this is a very ineffective way to clear the hot air. Unless you remove all the little metal protector from the PCIe slot, and place you Mac Pro in this orientation. Then all the hot air will able to get out easily to let the machine stay cool.
macpro2-1-jpg.487324
Click to expand...
Do you think that a USB powered fan pulling air out of the empty PCIe slots would have any effect or would it be too gutless?
 
OB-NZ said:
Do you think that a USB powered fan pulling air out of the empty PCIe slots would have any effect or would it be too gutless?
Click to expand...

i guess a fan like this may be more effective than a normal USB fan to pull the hot air out.
image.jpg

However, I never use it by myself, so can't give any comment, other than it may destroy of the beauty looking of the cMP :p
 
While any of the PCI-e slot fans mentioned above would exhaust the hot air out of the Mac Pro, they will also generate more noise, take up a slot, and will require routing another set of wires to power the fan. I wish Apple had included a little exhaust fan above the PCI-e slots.
 
Thanks for all of your replies! I'm not too interested in getting an extra blower for my PCI slots. My main interest is noise. I'd like a card that has the quietest built-in cooler possible, whether that may be the fan-blower style or the open-fan style. I feel as if the lower would be quieter, but I can't say for sure. However, if my frontal fans have to work harder in order to remove the hot air from an open-fan card, I'd skip that.

Seems to me like open-fan ones don't wear out as easily as fan blowers... is that true? It seems as though fan blowers can wear out easily, and when they do, they are LOUD. My fan-blower 5770 sounds like a motor.
 
PowerMac G4 MDD said:
Seems to me like open-fan ones don't wear out as easily as fan blowers... is that true? It seems as though fan blowers can wear out easily, and when they do, they are LOUD. My fan-blower 5770 sounds like a motor.
Click to expand...

That's pretty much impossible to know. I don't know of any source to find information on which brands and/or type of fans are most reliable. My theory is, hotter GPUs will require the fans on their cooler to work harder and more often. This will lead to shorter life spans and more noise.
 
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Few quick thoughts

You guys are forgetting that the area between side panel and PCIE slots is open to the cheese grater surface. So even if all the blocker plates are in there it is still pretty easy for air to get in and out.

In my experience, the reference fans are VERY long lived. The fans that I get dead most often are on 7950/70/R9 280x, etc that use dual or triple fans. Somehow those frequently die, I think they are lower spec. Frequently one or more will spin slower

AMD cards run hotter and burn their fans out soonest, simple fact. But I have several dead 7970s here, the fans are still fine, card long dead.

But that cheese grater design, super easy for air to get in and out, heat only gets a chance to rise when there is little air movement, the design itself keeps air moving.

I really like how latest Nvidia Dual Fan cards drop to NO fan movement below a certain threshold, this allows the PCIE fan to do all of the work, air all moving in one direction.

I also see the desire to use a "blower" style as this actually works with the cMP cooling system by feeding the air outside.

Keep in mind that ALL heat generated must be moved somewhere. So by definition, a card that produces the least heat, has the least heat to remove. GTX970 is great in this regard.

As a for-instance, I am working on a GTX980 flash job right now with ACX 2 cooler. When idling at desktop, fan never comes on. Only when I run Valley benchmark does the fan even start spinning, and even then not audibly. A 7970 would be ramping to a dull roar during this time. Meanwhile the 980 scores 50 fps with near silence, the 7970 gets a 35 fps score and makes some noise as test runs. Get an efficient card to begin with and your odds of silence are higher. And the fans themselves will last longer.
 
Such valuable insight! The issue would be finding a nice Nvidia card (flashed for 1,1 Mac Pro) that is neck-and-neck with the performance of my 5770 (or better) and is $100 or less. If I cannot, I may just go and buy this notable eBayer's good 5770s. He's a dealer, unlike the guy I purchased my current 5770 from.
 
PowerMac G4 MDD said:
The issue would be finding a nice Nvidia card (flashed for 1,1 Mac Pro) that is neck-and-neck with the performance of my 5770 (or better) and is $100 or less.
Click to expand...

If I recall correctly, there is no such thing. Only much older Nvidia cards can work with the MP 1,1. GT120 and 8800GT I think.
 
ActionableMango said:
If I recall correctly, there is no such thing. Only much older Nvidia cards can work with the MP 1,1. GT120 and 8800GT I think.
Click to expand...

My last card was an 8800GT 1GB, but the exposed fan on it is SO loud. I think I'll just end up getting a fan-blower 5770 that ISN'T a piece of garbage. Again, mine was from some random guy who had his old 5770 that he flashed for Mac. I found a dealer on eBay who responsibly flashes cards for Mac and sells them in wonderful condition. Hopefully his "quite" is my "quiet."
 
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