P180 airflow - fanless vga?

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rouin
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P180 airflow - fanless vga?

Post by rouin » Thu Aug 17, 2006 3:33 am

Hello. I am piecing together a new system very soon, and I was juggling with the idea of a fanless graphics card. It will probably be a GeForce 7600GT, mounted on an Intel motherboard with the new Conroe CPU. This will all be enclosed in a P180 case. I was thinking about getting a fanless system for the video card, maybe Zalman or something. My concern is that the ambient temperature inside the case would go too high, and I was wondering if there was enough airflow in the stock P180 case to give me the green light to invest in an aftermarket fanless graphics card kit. I won't be overclocking, or playing any uber-intense games.

Fat_bloater_dave
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Post by Fat_bloater_dave » Thu Aug 17, 2006 4:22 am

If you were going to go for any Case then the P180 is about the best airflow your gonna get so id say go for it.

Thomas
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Post by Thomas » Thu Aug 17, 2006 4:33 am

I dont have experience with the CPU and VGA mentioned.

But with a socket A 2800 Sempron and a Radeon 9800Pro/Zalman ZM-HP D, and amb. temp in the early 20 C's, I find it's a challenge to keep a front/rear 12 cm Nexus below 7 volt AND have a CPU temp below 50 deg. C. Except for hot summer, it seems to work in 2D mode, but 3D is a notorious challenge.

I think the 7600GT consumes less power, than a 9800Pro. I'm unsure about the CPU's... Try dig it up.

paulesko
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Post by paulesko » Thu Aug 17, 2006 5:47 am

I have a fanless 7600gt on my p180 and it´s overclocked (as mucch as I can) ;) with both exhausts nexus @ 6-7v its temp at idle is around 52 and 75 at full now in summer. Room temperature is about 25º here in spain.

darthan
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Post by darthan » Thu Aug 17, 2006 11:15 am

Going passive should work. It's important to remember that going truly passive isn't possible. You must have some airflow around anything hotter than a low power (X1300, 7300 etc.) card. Something like a 7600GT is going to require more than just random airflow to cool it passively, at least in 3D mode. You could go with a dedicated fan to do this, and set it to only turn on when the graphics card hits a certain temp, or you could just arrange to have a system fan that directs some amount of airflow in the direction of the card. It can be only a little airflow, but you're going to need it.

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Post by smilingcrow » Thu Aug 17, 2006 12:12 pm

I’m surprised how high GPU temps can be at idle even for basic cards. They really are designed to take a beating although I sympathise with people that are uncomfortable with idle temps as high as 90 – 100C.

I wonder if they are 100% stable at these temperatures? As they are typically only rendering a visual scene I don’t suppose it matters whether an occasional error occurs, unlike with a CPU. But using a GPU as a physics processor in a non gaming scenario is a different issue.

If they are 100% stable at these temperatures, it begs the question, why are desktop CPUs only good for 60 – 70C? Mobile CPUs are rated as high as 100C, so why are desktop CPUs rated so low compared to other types of processors! So many questions :)

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Post by MikeC » Thu Aug 17, 2006 2:05 pm

smilingcrow wrote:If they are 100% stable at these temperatures, it begs the question, why are desktop CPUs only good for 60 – 70C? Mobile CPUs are rated as high as 100C, so why are desktop CPUs rated so low compared to other types of processors! So many questions :)
There are 2 thermistors in modern AMD and Intel processors. One gives an approximation of the casing temperature, which you refer to. The other is used for emergency shutdown. It's set to simply turn off the CPU entirely somewhere around 125~135C. Check Intel & AMD reference CPU thermal docs.

drlove
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Post by drlove » Thu Aug 17, 2006 2:49 pm

I have saw another article that a fanless 7900 gt by gigabyte was actually cooler than a fanned counter part check this out.
http://www.tomshardware.com/2006/06/02/ ... page5.html

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Post by smilingcrow » Thu Aug 17, 2006 5:17 pm

MikeC wrote:There are 2 thermistors in modern AMD and Intel processors. One gives an approximation of the casing temperature, which you refer to. The other is used for emergency shutdown. It's set to simply turn off the CPU entirely somewhere around 125~135C. Check Intel & AMD reference CPU thermal docs.
I wonder why there’s such a large difference between the two temperature ranges; 65-70 and 125-135? Many BIOSs on Intel boards have the ability to turn off the CPU Thermal Monitoring (TM1 & TM2), which I deduce to be the feature whereby the CPU throttles its clock when the temperature reaches a certain limit. Am I deducing correctly here and does this mean that with this feature switched off you are free to explore running the CPU at higher temps without clock throttling? This is probably not a good anyway.

LemMinGs
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Post by LemMinGs » Sun Oct 01, 2006 6:34 pm

The thermal throttling is done on the cpu itself, AFAIK there is no way to disable it.

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Post by MikeC » Sun Oct 01, 2006 6:54 pm

smilingcrow wrote:
MikeC wrote:There are 2 thermistors in modern AMD and Intel processors. One gives an approximation of the casing temperature, which you refer to. The other is used for emergency shutdown. It's set to simply turn off the CPU entirely somewhere around 125~135C. Check Intel & AMD reference CPU thermal docs.
I wonder why there’s such a large difference between the two temperature ranges; 65-70 and 125-135?
Intel specifies a maximum outer casing temp in its reference docs for ensuring adequate cooling for CPUs. The standard technique is to grind a groove in the CPU heatspreader and epoxy a thermocouple at the center, and monitor the temps. One of those thermistors is meant to simulate the outer casing temp.

psiu
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Post by psiu » Mon Oct 02, 2006 6:35 pm

Sounds like maybe having the internal front mount fan (behind the upper HD cage) could be a solution. Even undervolted the van will get the airflow to the right spot and as long as the rest is exhausting up and back you should be okay I would think

Hamulus
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Post by Hamulus » Thu Oct 05, 2006 5:50 pm

I have a 6600LE passively cooled, with 3 120mm fans and a 92mm fan in my case, all at 12V(loud). With this setup I can only play BF2 for about 30-45min before the GPU shits itself (no fans blow directly on it, but if they need to, then it's not passive anymore, is it!). I have vowed never to passively cool again for a GPU! Mind you, the heatsink isn't that great on it compared to say the Asus 7600GT (that folds out), so you may be OK, but if it was me (and I was gaming) I would go for active cooling.

Also, a 7900GS is a great leap in performance with very little difference in price! They can be OCed to as good as a 7900GT. :)

snapshooter
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Post by snapshooter » Thu Oct 05, 2006 6:19 pm

I'm running C2D, fanless Gigybyte 7600GT inside a P180. My MB and VGA temp are 31 and 42 respectively when my room temp is about 22C. The key is to mount an internal fan on the upper hd cage and TURN OFF the top fan. It help reducing my VGA temp by about 6-7C.

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Post by smilingcrow » Mon Oct 09, 2006 11:08 am

LemMinGs wrote:The thermal throttling is done on the cpu itself, AFAIK there is no way to disable it.
The Thermal throttling is done purely by the CPU, but you can disable it using software such as RMClock. In effect there is a register on the chip that is either set to on or off. You can even trigger throttling manually with software, although you can’t change the temperature threshold AFAIK.

Engine
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Re: P180 airflow - fanless vga?

Post by Engine » Tue Oct 10, 2006 8:27 am

rouin wrote:It will probably be a GeForce 7600GT, mounted on an Intel motherboard with the new Conroe CPU. This will all be enclosed in a P180 case. I was thinking about getting a fanless system for the video card, maybe Zalman or something. My concern is that the ambient temperature inside the case would go too high, and I was wondering if there was enough airflow in the stock P180 case to give me the green light to invest in an aftermarket fanless graphics card kit.
Personally, I'd go with one of the coolers with heatpipes which wrap above or behind the card, which then connect to a heatsink which sits atop the card once mounted in the P180. If you then use any kind of ventilation blowing from the front of the case toward the rear exhaust, you'll get airflow over the VGA cooler, as well.

I'm considering doing the same thing, with two Nexus 120mm fans in a push-pull, one mounted to a Ninja on the CPU, one mounted at the exhaust position on the back of the P180. Then I'd like to cool the GPU with something like the HR-03 or the Condor.

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