Are PSUs with 80mm rear exhaust fans going to be discontinued?

[Anarchist420]

I've noticed a lot of PSUs have a top fan that's larger, and I don't like it that way as much. Hopefully my Antec Sig 650 will last at least 3.5 more years, but will there be PSUs with 80mm rear exhaust ball bearing fans 5 years from now?

 

[Fallengod]

I am not sure anyone has an answer to this as I doubt anyone here works for, designs or is involved with the manufacturing of power supplies, nor has a crystal ball to look into the future.

The only thing I could conclude is that there must be specific design reasons for building them the way they build them. I will say, power supplies are being built better and more efficient. We already have platinum efficiency rated power supplies which produce very little heat, thus probably not needing multiple fans. In fact, there are some gold and platinum rated power supplies that are fanless because of the high efficiency rating.

I personally do agree with you, I would rather have a fan pushing out the back rather than out the top but...meh. I run a corsair 650 watt v2 PSU and I can say the thing stays pretty damn cool.

Also, remember, smaller fans are always louder as well.

 

[fffblackmage]

Also, remember, smaller fans are always louder as well.

Generally, but there are always exceptions. My Antec NeoHE PSU has a dead silent (or darn close to it) 80mm fan, but my FSP Blue Storm II PSU's 120mm fan is very noticeable.


btw OP, is there a specific reason why you don't like the large top fans in PSUs?

 

[theAnimal]

I am not sure anyone has an answer to this as I doubt anyone here works for, designs or is involved with the manufacturing of power supplies, nor has a crystal ball to look into the future.

You'd be surprised, but the question is whether or not anyone would divulge info on future products.

I personally do agree with you, I would rather have a fan pushing out the back rather than out the top but...meh.

The fan location on the PSU does not change the airflow path; the fan on top (or bottom depending on orientation in the case) is pulling not pushing.

 

[Anarchist420]

Generally, but there are always exceptions. My Antec NeoHE PSU has a dead silent (or darn close to it) 80mm fan, but my FSP Blue Storm II PSU's 120mm fan is very noticeable.


btw OP, is there a specific reason why you don't like the large top fans in PSUs?

Because it exhausts the hot air more directly or it doesn't blow the hot air back into the case. I don't really care about fan noise unless it's due to a defect.

 

[jonnyGURU]

I don't think 80mm fan cooled PSU's are going to go away completely, but they're certainly becoming few and far between.

The thing is, the usefulness of 80mm fans just isn't there any more. An 80mm fan used to cool better because the fan pulled air THROUGH the power supply. When larger fans (120mm+) came out, they just redesigned the heatsinks to accept air pushing down onto them as opposed to blowing across them. There was a problem with this design though. The PSU would have a "hot spot" in the front (the side towards the inside of the PC) because only so much air pressure would build up inside the PSU housing before the air exhausted out the back.

Soon, "baffles" we're implemented to keep more air in the PSU, but 80mm fans still cooled the entire PSU better.

Now, so many PSU's have been designed around larger fans that they keep any components that need more cooling away from the front of the PSU. Also, PSU's are now so efficient that they don't need as much cooling as they used to. This has made the 80mm fan in the PSU virtually obsolete.

 

[kapalua12]

Ok, so if I want to replace my meager Dell 265 watt ATX PS with this one:

Corsair Professional Series Gold 650-Watt 80 Plus Gold,

does the Corsair draw air in from the BOTTOM of the Power Supply?

My current supply draws air from the back of the PS to keep air flowing from the front of the case through the Dell Optiplex 990 case to the rear.

Will the Corsair replacement help cool the inside of the case as it would then pull air directly from the area of the i7 Heatsink and might interfere with the efficiency of the Dell air flow front to back of the case which Dells typically do.

Also, the Dell PS seems to always be on. Would the Corsair fan on this more efficient PS (Corsair Gold) be more quiet and off at idle even with an i7 2600? and the heat it produces? As it is, with the Vertex 3 OS drive and no HDD installed (at the moment) the case only has the sound of the PS fan.

kapalua

 

[lehtv]

Corsair AX650 is like most PSUs these days, with the fan directly opposite to the PCB (where the PSU components are sitting). If your case has a top mount for the PSU, then it'll draw air from below.

 

[Anarchist420]

I don't think 80mm fan cooled PSU's are going to go away completely, but they're certainly becoming few and far between.

The thing is, the usefulness of 80mm fans just isn't there any more. An 80mm fan used to cool better because the fan pulled air THROUGH the power supply. When larger fans (120mm+) came out, they just redesigned the heatsinks to accept air pushing down onto them as opposed to blowing across them. There was a problem with this design though. The PSU would have a "hot spot" in the front (the side towards the inside of the PC) because only so much air pressure would build up inside the PSU housing before the air exhausted out the back.

Soon, "baffles" we're implemented to keep more air in the PSU, but 80mm fans still cooled the entire PSU better.

Now, so many PSU's have been designed around larger fans that they keep any components that need more cooling away from the front of the PSU. Also, PSU's are now so efficient that they don't need as much cooling as they used to. This has made the 80mm fan in the PSU virtually obsolete.

Thanks for your reply and your excellent reviews jonnyGURU🙂

 

[Zap]

does the Corsair draw air in from the BOTTOM of the Power Supply?

PSUs with a rear fan has the fan moving air OUT of the PSU. All other fan designs in a PSU has air moving IN to the PSU. Nothing to do with a particular brand.

 

[lehtv]

There's one exception, Antec CP-850 (and possibly some other Antec unit(s), not sure.)

EDIT: nvm, falls under "all other fan designs"

 

[jonnyGURU]

My current supply draws air from the back of the PS to keep air flowing from the front of the case through the Dell Optiplex 990 case to the rear.

No it doesn't. That's an exhaust fan. It's blowing OUT of the power supply.

Also, the Dell PS seems to always be on. Would the Corsair fan on this more efficient PS (Corsair Gold) be more quiet and off at idle even with an i7 2600? and the heat it produces?

It won't be off. That's a feature you only find on power supplies advertised as "semi-fanless". The fan will be at a lower RPM at lower loads and higher RPM's at higher loads. It WILL be quieter than your old Dell's power supply for the reasons I already mentioned: Larger diameter fans are inherently quieter than smaller fans, even at the same RPM.

 

[jonnyGURU]

There's one exception, Antec CP-850 (and possibly some other Antec unit(s), not sure.)

That's not a rear fan, though. That's an internal fan. So to reiterate what Zap said, all internal fans suck air INTO the power supply. Then positive pressure pushes the heat out the back. If the fan is external, it's sucking air OUT of the power supply.

 

[lehtv]

yeah ur right

 

[mindless1]

I've noticed a lot of PSUs have a top fan that's larger, and I don't like it that way as much. Hopefully my Antec Sig 650 will last at least 3.5 more years, but will there be PSUs with 80mm rear exhaust ball bearing fans 5 years from now?

Yes there will be. There will always be a sufficient number of oddball case configurations to allow at least one manufacturer to sell sufficient volume to make it worthwhile. Maybe it'll be a brand you "like", or maybe not.

Regardless, a quite large user base demonstrates that bottom/intake fan PSU designs work fine, though in cheaper units with sleeve bearing fans the fan can be short lived. Is bottom intake the ultimate perfect design? Not necessarily, but it doesn't need to be, that it works is enough. People make a lot of fuss about a minor difference sometimes.