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Topic: Read BEFORE buying Graphics card - page 2. (Read 9359 times)

legendary
Activity: 1855
Merit: 1016
August 02, 2011, 12:06:42 AM
#6
I usually go for the closed type because it makes ducting the air easier. But they don't actually draw air from the ass. Air is drawn in through the fan, it's a centrifugal fan. The opening on the ass exhaust as well.

Quote
Here CLOSED type works better.
In closed type air is sucked from mouth of the card & it passes to the GPU & comes out of the ass(back) of the card.
Their is NO GAP for the air to escape in any side.
This makes the air coming out of card is VERY hot. But it cools the GPU.
Since it SUCKS air, even in multi card setup, it doesn't increase the heat of near by card, since the air never escapes on sides.
Air goes OUT only on cards ass.
newbie
Activity: 42
Merit: 0
August 01, 2011, 03:46:41 PM
#5
Any one object this or has some other experiences can share.
I want to know the pros & cons of the different design, so if i buy cards in future it must be a correct one.

I usually go for the closed type because it makes ducting the air easier. But they don't actually draw air from the ass. Air is drawn in through the fan, it's a centrifugal fan. The opening on the ass exhaust as well.

For the open type, you could "fix" it by making a plastic shroud to guide the hot air out, but this tends to reduce the cooling performance for each card.
But if you plan it properly, you could offset that by directing cooler air into the intake and directing the hot air away.

I'm personally halfway through making an large airduct for my entire PC drawing all the rear exhaust eventually out the window.
member
Activity: 98
Merit: 11
August 01, 2011, 03:22:40 PM
#4
one option is to take the plastic off of the OPEN type and put fans to 0 speed, but only if you have a high cfm case fan(s) blowing at the top of the cards (like you have in the pic). That way you're not dealing with the gpu fans screwing up the airflow distribution. By high cfm I mean the deltas that push 150-240cfm.

Of course in a closed case you need the same thing + a case fan in front to push air in, and another case fan pulling hot air out from the back.
member
Activity: 97
Merit: 10
August 01, 2011, 02:52:47 PM
#3
I've noticed a similar problem:
Closed cards (usually "reference" ATI cards) run significantly cooler than open (non-reference) cards.  The largest advantage to non-reference cards that I've seen is that they're shorter and fit easier into more cramped cases.  Also, reference cards usually run a lot louder at full fan speeds than non-reference cards, though quieter when running at the same temperature.
hero member
Activity: 711
Merit: 500
August 01, 2011, 01:32:31 PM
#2
Have you tried blowing air the horizontally, maybe push pull with fans at front and back
legendary
Activity: 1855
Merit: 1016
August 01, 2011, 11:22:30 AM
#1
Note/Advice/Tips/Guide to those who going to buy graphic cards.

I was fooled by some other fool/fools who designed graphic cards.
2 types of card design i see & i call it OPEN type & CLOSED type. I don't know what manufactures use to call.

Example for OPEN type card is R6970 Lightning card.
http://www.msi.com/product/vga/R6970-Lightning.html

Example for CLOSED type card is MSI R6970-2PM2D2GD5 card.
http://www.msi.com/product/vga/R6970-2PM2D2GD5.html

I bought 4 nos. of OPEN type, R6970 Lightning, since it is factory over clocked to 940Mhz & also has TWO FANS.
I thought since it has TWO FANS & ITS MILITARY DESIGN, it will run much cooler than the other type.
But i was WRONG.

Actually this is foolish design to use in a multi GPU card setup. This type of cards MUST NOT be used if more than 2 cards in a pc.

In my mining setup, 6 cards are connected from slot1 to slot6 using riser cables, with more than 1 inch gap between each cards.
The LAST card in slot 6 , grabs air from open, while the card before that grabs air from back of last card & it goes on.....with FIRST card getting air from back of second card.
Here comes the problem.
The last card runs cooler(65C) & the FIRST card runs HOTTER than all (>95C)

What happens here is the last card grabs air from outside & the card design allows air to come out of the card in ALL directions.
If you look at the card, you can see there is gap in ALL 4 sides of the card for the air to escape.
The fan grabs air, pushes to the heat sink & the hot air escapes from all sides.
The card before the last card, grabs the HOT air from last card, & gets temperature increased & air escapes through all sides.
As this goes on, the FIRST card gets hottest air & so the temperature of the card is very high.
Placing 6 120mm fans on top of cards don't reduce much temperature. Only up to 85C.

Here CLOSED type works better.
In closed type air is sucked from mouth(centrifugal fan in one side of card) of the card & it passes to the GPU & comes out of the ass(back, where varies connectors are placed) of the card.
Their is NO GAP for the air to escape in any side.
This makes the air coming out of card is VERY hot. But it cools the GPU.
Since it SUCKS air, even in multi card setup, it doesn't increase the heat of near by card, since the air never escapes on sides.
Air goes out only on cards ass.

But this type also has another problem.
Since it sucks air from mouth & release hot air through ass & NO GAP for air to escape in any side, DUST if accumulated on the ass will NOT allow the hot air to go out easily.
So, it needs to be looked in to every now & then to keep the ass clean.
If not the hot air will fry the GPU & you get BAD smell.

My mining rig cabinet is made with slotted angles, just a skeleton of iron angles, same like cablesaurus A1 model cabinet.
A1 model cabinet is made with aluminium frame, mine is with slotted angles.





Any one object this or has some other experiences can share.
I want to know the pros & cons of the different design, so if i buy cards in future it must be a correct one.
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