huge heat problem

evilmonkey

Limp Gawd
Joined
Dec 16, 2003
Messages
151
My friend has a Tyan MPX board with 2x 2400MP processors and they are running HHHOOOOOOOTTTTT. We sort of rewired the case to increase airflow (moving extra cables around the back, etc). I recently checked the temps using sandra and was surprised at what I found

temps.jpg
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Any suggestions?
 

dagamore

Gawd
Joined
Oct 25, 2002
Messages
649
what sort of cooling is he using, i.e. what HSF combo?

is the PSU pulling enough air out, you might want to put in a chimnney fan (one on the top) to pull hot air out of the system.

is that the load temp or idle?

I have had good luck cooling dowm hot dual AMD setups with the zalman 6000 cu HSF.


also what case are you using, and does it have an exhaust fan by the cpus? is it installed, if so what size?

you might want to look in to ducting the HSF with cold outside the case air.

what is the room temp it is in at?
 

evilmonkey

Limp Gawd
Joined
Dec 16, 2003
Messages
151
he is using the stock amd retail heatsink fans, aluminum or whatever

power supply is a 400W that came in the case, which is the Antec 1040bx ii i believe

those temps were taken about a minute after startup, so i would say idle

there are 2 80mm fans, one intake one exhaust. if i were to convince him to make a chimney what about the idea of a 120mm exhause in the top and then switching the two 80mm fans to intake (one front intake one rear intake)

as for his room temperature it's by no means cool/cold. i would have to guess it's about 75 F or so at any given time depending if the tv is one, etc.
 

grugar

n00b
Joined
Jun 17, 2004
Messages
42
have you also taken a look in the Bios for the temps?
have you touched the heatsinks, are they also so hot?
75°C is extrem, especially for the board,in hope for you i think sandra reads b******t.
 

DanK

Gawd
Joined
Apr 21, 2004
Messages
948
i bought this case from newegg http://www.newegg.com/app/ViewProductDesc.asp?description=11-150-017&depa=1

it comes with 2 90mm fans. i dremeled out the 80mm front intake to 90mm, and put the top exhaust fan there blowing in. i left the side fan as is for the time being. i put an enermax 2-ball-bearing fan that i already had at the top blowing out, it moves a lot of air and is quiet. The case pics at newegg are old, the newest revision of that case has space for a single 120mm exhaust fan. I also dremeled out a 120mm spot in the bottom of the case to mount an intake to blow up across the system. I use temperature-controlled fans, made by vantec, for the 120s. Also, I put furniture feet under the bottom to help the intake.

Right now my temps. are around 50 degrees C at idle. (Ambient is 32 degrees.) Not great, but this is decent considering how horribly Volcano 11s are suited for dual boards. (I'm in the market for new heatsinks now.) Changing cases made about a 5-7 degrees difference. The case is very inexpensive as cases go, and isn't shoddy or unsturdy.

As for heatsinks, I'd recommend a hybrid of aluminum with a copper core, preferably with heatpipes. The more surface area, the better. This is of course if you choose air cooling. There are other methods, like water cooling, that are outside my experience.

P.S. I can take pics of my setup/modifications to the case if you'd like.
 

sandmanx

[H]F Junkie
Joined
Mar 22, 2001
Messages
9,902
I've got the same setup on a couple machines here where I work, and they idle around 50C. I'm using a generic zipzoomfly case with 450w PSU's in them, and I've got an 80mm fan in the front and back of the case. I'd say ambient temp is around 75-80F normally around here. Those temps sound extremely high, and sounds like a major airflow problem if it's reading correct. I'm using the stock MP heatsinks on mine as well.
 

dagamore

Gawd
Joined
Oct 25, 2002
Messages
649
i would get rid of the stock hsf they are ok if you run them around 4k rpm or better and if you have them in a room temp under 25c (~70f IIRC) and put in alot ber ones, i like the zalman 6000s they cool great, and mount right up to the lugs on the socket, you dont need to remove the MB to get them on or off. also if you used the stock thermal x-fer pad on the HSF i would get rid of it and put on some good thermal compound, like AS3 or the like.

i run 3 duals with the 6000's and they all work great, you might have to mod the corners to fit next to eachother like i did on the dual amd MP board, but thats it.my load temps never go over 45c with the zalmans, and i keep my room near 30c (damn 80 and 120 galon fish tanks :D)

and any hole in the top of the case will help even if it dont have a fan in it.
 

evilmonkey

Limp Gawd
Joined
Dec 16, 2003
Messages
151
well it turns out you were right and sandra was BS. he downloaded the monitoring utility from tyan specially for his board and took temps again and it seems they were really like 38C for cpu1 and 42C for cpu2. seems odd to me that there would be a discrepancy so large as what he got, but oh well i guess temps aren't as bad as they seemed at first
 
Joined
Jun 11, 2000
Messages
693
It's all about airflow!! I don't care what HSF combo you've gotten, if you don't have good airflow to take the heat away from the case, you've gotten nothing! :)
 

SneakX

Limp Gawd
Joined
Jun 21, 2002
Messages
361
You should definitely change the stock fans, I saw too many MPs overheating at my workplace (sometimes you can smell heat or even see some sort of "sweat" around the core), and we had to change almost every stock fans for Thermaltake Volcano 10 under warranty :/ Airflow is also a major factor as everybody is saying :p
 
I

Ice Czar

Guest
spikegifted said:
It's all about airflow!!

and its ambient temperature

Im recycling posts tonight sorry Im kinda busy :p

--------------------------------------------------------------------------------------------------------------


a good read >
General Heat Transfer Guide @ amdmb written specifically about the thermodynamics of computers, and focusing on aircooling
ProCooling Article base well worth a browse, also check the forum and specifically the ProCooling Staff Worklogs

one of the things you can draw from the first article is
The heat transfer through the wall follows a simple equation:
Q=k/L(T1-T2)

my comments below in italics
We can draw some interesting conclusions from this equation. First, heat transfer is proportional to the temperature difference on the object. If the temperature differential doubles, the heat transferred doubles.If the temperature of your air is colder the efficiency increases Second, the conduction coefficient "k" is proportional to heat transfer. If the conduction coefficient doubles, the heat transfer doubles.Applys to the material, generally copper, which has a better conduction coefficient than say aluminum Alternatively, for the same differential temperature, twice as much heat may be transferred. The final observation is "L". As thickness increases, heat transfer decreases. Alternatively, to maintain the same heat transfer through a material twice as thick requires twice the temperature differential.

that happens to be for conduction, but there is a corrallary for convection (transfer from the heatsink to a fluid (air\water\ect)
its known as Newton's Law of Cooling

so what the hell is my point? :p
whatever thermal solution you have is typically rated with a °C/W rating (Thermal Resistance (Rht) in °C/W actually)

Delta = CPU temp - Ambient Temp
C/W = Delta / CPU Watts

Interpreting C/W: For every watt (CPUw) that the CPU consumes, the HSF will limit the CPU's temperature rise to (C/W x CPUw) plus the temperature at the HSF's fan inlet. For example, at an ambient temp of 25 C, a C/W of 0.25 with a CPU radiating 50 watts means that CPU temp will increase 50 x 0.25 = 12.5 C over ambient temp, or 37.5 C. The lower the C/W, the better.
and the lower the Ambient Temperature too
basically the thermal resistance of a given solution changes with the temperature differential, which is why thermal solutions are rated in °C/W which leaves that variable ambient open but gives you a formula

and considering that 400btu\hr = 117.2 Watts.....
think you need to add up approximately what the assorted components are probably going to consume >
CPU Thermal Power In Watts &
takaman's Power Supply Calculator
(those being the theoretical maximum) plus the efficiency of the Power Supply itself (80% meaning 20% is converted to heat) and of course any peltier adds more heat to the load

Then based on the expected ambient, search for a sealed thermal solution with a °C/W rating capable of actually meeting the job description. Offhand Id say your not looking for a smaller exchanger at all, considering the poor heat transfer because the temperature differential is going to be substantially closer than in say.... my room\enclosure (which is at 15C \ 60F with AC ) maybe you should consider a large radiator\stand\enclosure for your dock, you really need to have enough surface area to dissipate thyat heat at a closer differential temperature and thats going to be a challenge

--------------------------------------------------------------------------------------------------------------

alot of applicable stuff if not directly addressing the same exact question
.
 

tiebird321

[H]ard|Gawd
Joined
Jun 6, 2004
Messages
1,062
anyone taken the idea the the software might be reporting the Temps wrong. the temps sandra displays on my 760mpx board have no relation to the temps listed in the bios, and the temps found on a thermal probe mounted to the underside of the CPU

the sandra temps tend to run about 30C high
on my board (Tyan)
 
I

Ice Czar

Guest
thats why there is an offset available in MBM, if you can deterime the value to enter
you have to consider there are alot of different sensor\SMBus chip combinations
so actually determining the correct temperature becomes probelmatic
and certain implementations are notoriously inaccurate
 

dagamore

Gawd
Joined
Oct 25, 2002
Messages
649
since there iws such a large temp difference, i would look at geting a temp prob (i like my infrared one from radio shack) and see if you can get a temp of the HSF at the base, or put a remote sensor, like the one from a digi doc, or compu nurse, next to the cpu and see if posibly the bios is alos reading the sensor wrong.


and spike is right about air flow, it does matter, alot, but a good hsf will perform ok in poor air flow, but a stock fan will not perform at all in a poor air flow case.

and who ever stated the temp differance was also right, the colder the air around the hsf (what ever one you use) will work better.

hope that this is not a real problem and you have it fixed :D i found that the tyan system monitor was within 2C of the real temp of my cpus at all times, and thats good enough for me :D
 
I

Ice Czar

Guest
I know there was a BIOS update for my K8W to address a CPU Temperature inaccuracy in the BIOS (V1.02)

thats always worth checking regardless of the mobo ;)
 

mosin

[H]ardForum Junkie
Joined
Sep 30, 2001
Messages
6,558
The voltage on his 12v rail sucks. I'd change out the power supply, if that were my rig.

I'm glad you got the heat reading straightened out. :)
 
I

Ice Czar

Guest
mosin said:
The voltage on his 12v rail sucks..

I missed that, and its way out of spec if accurate (which it might not be)

minimum +11.4 V to +12.6 V Maximum ( a 5% varience)
 

fubar569

[H]ard|Gawd
Joined
Dec 16, 2003
Messages
1,743
I had very good luck with my XP1700 & 2100 overclocked to 2.38ghz (140fsb) in my Gigabyte dually board with SLK-900A's and 92mm Tornadoes at full blast...temps of course depend on ambient but never have peaked above 55c under full 100% load with the door closed...i've seen them as low as 38c under light usage...
 
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