Is there a 'check' in place to stop the CPU from frying if the heatsink fan fails ?

[Arif]

Hi folks,

I understand that the CPU will 'fry' within a few seconds if the PC is
switched on without the heatsink and fan fitted.

What is the situation if the heatsink and fan are fitted but say the
fan stops and only the heatsink is left to dissipate the heat. How
long before the CPU 'dies' ?

Are there any checks in place to stop the PC from starting if the fan
dies ?

Do any 'alarm' bells go off if it does happen to tell us to switch off
the PC immediately ?

Is there any 'forewarning' that the fan is about to die ? (similar to
the 'SMART' diagnostics for hard disks ?

(In case this is motherboard specific, the motherboard in question is
Asus A7N8X Deluxe V2)

What precautions can one take to avoid this scenario ?

TIA,
Arif

 

[Neil]

the majority of not all of the newer boards say kt333 chipset and up have
this safety feature enabled now.



Neil
http://members.rogers.com/nasrott

 

[[NAC]Nubi]

well its easy isnt it? best way to avoid that problem is..."Never turn
your/any rig on that dosent have a HSF on the cpu..." duh...

 

[Egil Solberg]

Hi folks,

I understand that the CPU will 'fry' within a few seconds if the PC is
switched on without the heatsink and fan fitted.

What is the situation if the heatsink and fan are fitted but say the
fan stops and only the heatsink is left to dissipate the heat. How
long before the CPU 'dies' ?

Are there any checks in place to stop the PC from starting if the fan
dies ?

Do any 'alarm' bells go off if it does happen to tell us to switch off
the PC immediately ?

Is there any 'forewarning' that the fan is about to die ? (similar to
the 'SMART' diagnostics for hard disks ?

(In case this is motherboard specific, the motherboard in question is
Asus A7N8X Deluxe V2)

What precautions can one take to avoid this scenario ?

With your mobo you will be very safe. Your mobo will probably manage a
situation where the heatsink isn´t installed at all. But DONT TRY!
Pre-KT333 mobos (with some exceptions) don´t have the feature where mobo
circuits will shut the CPU down if thermal diode (inside CPU) reports a temp
over a certain limit. You have that feature.

Older mobos had an external temp diode located under the CPU. This one would
react too slow in a scenario where the heatsink wasn´t installed, and the
CPU would fry. If fan stops spinning, this feature would probably save the
CPU, though. Some mobos come with this external diode in addition to the
protection offered by the internal.

And last but not least, some mobos refuse to start if they cannot detect a
fan speed above a certain limit. You can configure BIOS to shut down CPU if
fan speed drops under a limit of your choice.

In your case, if fan stops, there could be 2 or 3 features shutting down
machine and saving your CPU. That´s pretty good.

In a scenario where a heatsink falls off, CPU could be saved with the first
mentioned method. But >300g of free moving metal inside the case is likely
to destroy other parts of the machine.

 

[Wes Newell]

I understand that the CPU will 'fry' within a few seconds if the PC is
switched on without the heatsink and fan fitted.

What is the situation if the heatsink and fan are fitted but say the
fan stops and only the heatsink is left to dissipate the heat. How
long before the CPU 'dies' ?

That all depends on a lot of factors. It may never die, depending on the
MB and/or what you have running. Just sitting idle I could easily unplug
my fan without a problem since I'm running Lvcool. Some MB's offer
protection if you try an turn the system on and a fan isn't detected. Etc.

Are there any checks in place to stop the PC from starting if the fan
dies ?

Depends on MB.

Do any 'alarm' bells go off if it does happen to tell us to switch off
the PC immediately ?

If you set it up.

Is there any 'forewarning' that the fan is about to die ? (similar to
the 'SMART' diagnostics for hard disks ?

Not that I'm aware of. Unless you want to consider low rpms a warning.

(In case this is motherboard specific, the motherboard in question is
Asus A7N8X Deluxe V2)

Should have put this at the top.

What precautions can one take to avoid this scenario ?

RTFM.

 

[Neil]

beleive he was asking if a fan quit working while sink was on.

well its easy isnt it? best way to avoid that problem is..."Never turn
your/any rig on that dosent have a HSF on the cpu..." duh...

Hi folks,

I understand that the CPU will 'fry' within a few seconds if the PC is
switched on without the heatsink and fan fitted.

What is the situation if the heatsink and fan are fitted but say the
fan stops and only the heatsink is left to dissipate the heat. How
long before the CPU 'dies' ?

Are there any checks in place to stop the PC from starting if the fan
dies ?

Do any 'alarm' bells go off if it does happen to tell us to switch off
the PC immediately ?

Is there any 'forewarning' that the fan is about to die ? (similar to
the 'SMART' diagnostics for hard disks ?

(In case this is motherboard specific, the motherboard in question is
Asus A7N8X Deluxe V2)

What precautions can one take to avoid this scenario ?

TIA,
Arif

 

[QED, eh ?]

I use Motherboard monitor with XP.
In "temp.s", check "enable alarm" (say 65C).
Check "when alarm goes off, start appl.n" <shutdown.exe>
With switch <-s -f -t 00> for instant shutdown.
Works fine on my Abit KT7a - and I get peace of mind.

 

[bigbrian]

Laugh, Can you make a Quick Time Video of you unplugging the fan? and we can
see how long it takes ..
I would say that IF, IF, and a big IF on top of it.. You have say 2 intake
fans and 1 exit fan + PSU draw in/exit fan (the draw fan is of course
straight over the cpu) then you might survive it just based on airflow
within the case, but generally speaking, no fan on your heatsink means it
will go to a high temp and shut down.. Software coolers dont make a
difference on todays processors. my cpu fan is only 1300 rpm and it does the
job nicely

Yep. I have my Zalman 7000 cpu cooler running at 1350 rpm, with no
other fans at all (except the one fan in the Zalman 400W PSU). No case
fans, nothing. The machine's totally inaudible from 4 feet away and
running at 42 degrees. I could get that down with a case fan or two,
but I'm wondering why I need to

Brian

 

[Ed]

Yep. I have my Zalman 7000 cpu cooler running at 1350 rpm, with no
other fans at all (except the one fan in the Zalman 400W PSU). No case
fans, nothing. The machine's totally inaudible from 4 feet away and
running at 42 degrees. I could get that down with a case fan or two,
but I'm wondering why I need to

Brian

My moto is, if it's stable then it's cool enough. ;p
Ed

 

[Wes Newell]

Laugh, Can you make a Quick Time Video of you unplugging the fan? and we can
see how long it takes ..

I'm running right now with the fan unplugged. No video, but here's what I
got temp wise. The first is with the fan running. The last is current
time. Vantec Aeroflow cooler. Notice how the system temp dropped with the
cover off.

[wes@wes2 wes]$ sensors
via686a-isa-6000
Adapter: ISA adapter
Algorithm: ISA algorithm
CPU core: +1.63 V (min = +1.48 V, max = +1.89 V)
+2.5V: +2.50 V (min = +2.13 V, max = +2.77 V)
I/O: +3.37 V (min = +3.01 V, max = +3.69 V)
+5V: +5.01 V (min = +4.51 V, max = +5.54 V)
+12V: +12.21 V (min = +11.22 V, max = +13.71 V)
CPU Fan: 5322 RPM (min = 3103 RPM, div = 2)
Sys Fan: 2743 RPM (min = 0 RPM, div = 2)
SYS Temp: +29.2°C (limit = +45°C, hysteresis = +40°C)
CPU Temp: +32.2°C (limit = +60°C, hysteresis = +55°C)
SBr Temp: +32.9°C (limit = +55°C, hysteresis = +50°C)

[wes@wes2 wes]$ sensors
via686a-isa-6000
Adapter: ISA adapter
Algorithm: ISA algorithm
CPU core: +1.63 V (min = +1.48 V, max = +1.89 V)
+2.5V: +2.50 V (min = +2.13 V, max = +2.77 V)
I/O: +3.37 V (min = +3.01 V, max = +3.69 V)
+5V: +5.01 V (min = +4.51 V, max = +5.54 V)
+12V: +12.21 V (min = +11.22 V, max = +13.71 V)
CPU Fan: 0 RPM (min = 3103 RPM, div = 2)
Sys Fan: 2732 RPM (min = 0 RPM, div = 2)
SYS Temp: +25.2°C (limit = +45°C, hysteresis = +40°C)
CPU Temp: +34.6°C (limit = +60°C, hysteresis = +55°C)
SBr Temp: +30.9°C (limit = +55°C, hysteresis = +50°C)

 

[rstlne]

Yea, well, if youg et a 2c change by removing the fan, then that tells me
something is BAD wrong with your system, cause it's not telling you the
correct temps..

Etc.

Laugh, Can you make a Quick Time Video of you unplugging the fan? and we can
see how long it takes ..

I'm running right now with the fan unplugged. No video, but here's what I
got temp wise. The first is with the fan running. The last is current
time. Vantec Aeroflow cooler. Notice how the system temp dropped with the
cover off.

[wes@wes2 wes]$ sensors
via686a-isa-6000
Adapter: ISA adapter
Algorithm: ISA algorithm
CPU core: +1.63 V (min = +1.48 V, max = +1.89 V)
+2.5V: +2.50 V (min = +2.13 V, max = +2.77 V)
I/O: +3.37 V (min = +3.01 V, max = +3.69 V)
+5V: +5.01 V (min = +4.51 V, max = +5.54 V)
+12V: +12.21 V (min = +11.22 V, max = +13.71 V)
CPU Fan: 5322 RPM (min = 3103 RPM, div = 2)
Sys Fan: 2743 RPM (min = 0 RPM, div = 2)
SYS Temp: +29.2°C (limit = +45°C, hysteresis = +40°C)
CPU Temp: +32.2°C (limit = +60°C, hysteresis = +55°C)
SBr Temp: +32.9°C (limit = +55°C, hysteresis = +50°C)

[wes@wes2 wes]$ sensors
via686a-isa-6000
Adapter: ISA adapter
Algorithm: ISA algorithm
CPU core: +1.63 V (min = +1.48 V, max = +1.89 V)
+2.5V: +2.50 V (min = +2.13 V, max = +2.77 V)
I/O: +3.37 V (min = +3.01 V, max = +3.69 V)
+5V: +5.01 V (min = +4.51 V, max = +5.54 V)
+12V: +12.21 V (min = +11.22 V, max = +13.71 V)
CPU Fan: 0 RPM (min = 3103 RPM, div = 2)
Sys Fan: 2732 RPM (min = 0 RPM, div = 2)
SYS Temp: +25.2°C (limit = +45°C, hysteresis = +40°C)
CPU Temp: +34.6°C (limit = +60°C, hysteresis = +55°C)
SBr Temp: +30.9°C (limit = +55°C, hysteresis = +50°C)

 

[Wes Newell]

Yea, well, if youg et a 2c change by removing the fan, then that tells me
something is BAD wrong with your system, cause it's not telling you the
correct temps..

Changed from what I really wanted to say, to this.
And this reply tells me that you need to learn a lot more before trying to
give advice.

That all depends on a lot of factors. It may never die, depending on the
MB and/or what you have running. Just sitting idle I could easily unplug
my fan without a problem since I'm running Lvcool. Some MB's offer
protection if you try an turn the system on and a fan isn't detected. Etc.

Laugh, Can you make a Quick Time Video of you unplugging the fan? and we can
see how long it takes ..

I'm running right now with the fan unplugged. No video, but here's what I
got temp wise. The first is with the fan running. The last is current
time. Vantec Aeroflow cooler. Notice how the system temp dropped with the
cover off.

[wes@wes2 wes]$ sensors
via686a-isa-6000
Adapter: ISA adapter
Algorithm: ISA algorithm
CPU core: +1.63 V (min = +1.48 V, max = +1.89 V)
+2.5V: +2.50 V (min = +2.13 V, max = +2.77 V)
I/O: +3.37 V (min = +3.01 V, max = +3.69 V)
+5V: +5.01 V (min = +4.51 V, max = +5.54 V)
+12V: +12.21 V (min = +11.22 V, max = +13.71 V)
CPU Fan: 5322 RPM (min = 3103 RPM, div = 2)
Sys Fan: 2743 RPM (min = 0 RPM, div = 2)
SYS Temp: +29.2°C (limit = +45°C, hysteresis = +40°C)
CPU Temp: +32.2°C (limit = +60°C, hysteresis = +55°C)
SBr Temp: +32.9°C (limit = +55°C, hysteresis = +50°C)

[wes@wes2 wes]$ sensors
via686a-isa-6000
Adapter: ISA adapter
Algorithm: ISA algorithm
CPU core: +1.63 V (min = +1.48 V, max = +1.89 V)
+2.5V: +2.50 V (min = +2.13 V, max = +2.77 V)
I/O: +3.37 V (min = +3.01 V, max = +3.69 V)
+5V: +5.01 V (min = +4.51 V, max = +5.54 V)
+12V: +12.21 V (min = +11.22 V, max = +13.71 V)
CPU Fan: 0 RPM (min = 3103 RPM, div = 2)
Sys Fan: 2732 RPM (min = 0 RPM, div = 2)
SYS Temp: +25.2°C (limit = +45°C, hysteresis = +40°C)
CPU Temp: +34.6°C (limit = +60°C, hysteresis = +55°C)
SBr Temp: +30.9°C (limit = +55°C, hysteresis = +50°C)

 

[rstlne]

Changed from what I really wanted to say, to this.

And this reply tells me that you need to learn a lot more before trying to
give advice.

Shrug, Say what you want, I am calling your "Reports" pure and utter BS..
Tho it might not be intentinal by you. Going by your "Little Test" an
athlon would be ideally suited to running in a fully passive state, and
these chips are NOT MADE and DO NOT WORK for solid state cooling, All you
have to do is work back the minimum power dissipation for a unloaded athlon
and you'll see that your numbers there alone are too low.. But hey, What do
I know eh
I guess external factors, Ceeling Fan, Under an AC, Over an AC Vent, or
something similar could be a large factor. but oh well

 

[Wes Newell]

Shrug, Say what you want, I am calling your "Reports" pure and utter
BS..

So now I'll go back to my usual abusive self and just say you don't know
wtf you're talking about. You wanted proof. I give it to you and you
basically don't believe it. That's your choice.

Tho it might not be intentinal by you. Going by your "Little Test" an
athlon would be ideally suited to running in a fully passive state, and
these chips are NOT MADE and DO NOT WORK for solid state cooling, All
you have to do is work back the minimum power dissipation for a unloaded
athlon and you'll see that your numbers there alone are too low.. But
hey, What do I know eh

Not very much.

I guess external factors, Ceeling Fan, Under an AC, Over an AC Vent, or
something similar could be a large factor. but oh well

No, but something called Stop Grant could be. Get the amd docs and find
out what it is.

Or just unscramble this. that should keep you away for a week or two.

Table 1. Electrical and Thermal Specifications for Processors with a CPUID
of 680 Frequency in MHz (Model Number) VCC_CORE (Core Voltage) ICC
(Processor Current) Thermal Power5 Maximum Die Temperature Working State
C0 Stop Grant S11, 2, 3, 4 Maximum Typical Maximum Typical Maximum Typical
1467 (1700+) 1.50 V 32.9 A 29.9 A 5.87 A 3.7 A 49.4 W 44.9 W 90°C 1533
(1800+) 34.0 A 30.9 A 51.0 W 46.3 W 1600 (1900+) 35.0 A 31.8 A 52.5 W 47.7
W 1667 (2000+) 1.60 V 37.7 A 34.2 A 7.68 A 4.7 A 60.3 W 54.7 W 1.65 V 36.5
A 33.2 A 8.85 A 5.4 A 1733 (2100+) 1.60 V 38.8 A 35.2 A 7.68 A 4.7 A 62.1
W 56.4 W 1800 (2200+) 1.65 V 41.2 A 37.4 A 8.85 A 5.4 A 67.9 W 61.7 W
85°C

 

[Matt]

beleive he was asking if a fan quit working while sink was on.

The BIOS normally has "Fan fail alarm" - though not sure if that also
means shutdown if the situation continues.

The conventional under-CPU heat sensing OUGHT to be fast enough for
thermal protection if the fan fails but the heatsink is still
attached, since the heatsink provides thermal mass and some cooling
effect. A mostly closed, fine finned haetsink will be worse than a
more open design under these conditions.

The forewarning of fan fail that MIGHT be noted are:
1. Gets noisy, particularly the groan of a fan with bearing trouble
2. If you monitor speeds (and they aren't being varied automatically)
Speed is lower than normal, or varies beyond the usual measurement
flutter.

well its easy isnt it? best way to avoid that problem is..."Never turn
your/any rig on that dosent have a HSF on the cpu..." duh...

Hi folks,

I understand that the CPU will 'fry' within a few seconds if the PC is
switched on without the heatsink and fan fitted.

What is the situation if the heatsink and fan are fitted but say the
fan stops and only the heatsink is left to dissipate the heat. How
long before the CPU 'dies' ?

Are there any checks in place to stop the PC from starting if the fan
dies ?

Do any 'alarm' bells go off if it does happen to tell us to switch off
the PC immediately ?

Is there any 'forewarning' that the fan is about to die ? (similar to
the 'SMART' diagnostics for hard disks ?

(In case this is motherboard specific, the motherboard in question is
Asus A7N8X Deluxe V2)

What precautions can one take to avoid this scenario ?

TIA,
Arif

 

[rstlne]

No, but something called Stop Grant could be. Get the amd docs and find

out what it is.

You'll never keep me away!
Okay, so, your saying your pc was issued a Stop Grant call of sorts then?

now, your the master on this, so
a) does these boards ship with the function enabled, if so will the
northbridge controll it
and
b) if you took a temp sample, then isnt it possible that your processor just
came out of SGS once it cool'd down

 

[Barry Watzman]

Intel processors do have such protective circuitry, AMD processors do not.

Some time ago (more than a year ago) this was covered in detail on Tom's
Hardware Guide. They even had a video showing what happened if the CPU
was run with no heatsink at all. The Intel CPU shut down. The AMD CPU
went up in smoke (literally). The video and the article may still be on
the site.

 

[bp]

Intel processors do have such protective circuitry, AMD processors do not.

Some time ago (more than a year ago) this was covered in detail on Tom's
Hardware Guide. They even had a video showing what happened if the CPU
was run with no heatsink at all. The Intel CPU shut down. The AMD CPU
went up in smoke (literally). The video and the article may still be on
the site.

That's old stuff.
Most new MBs have some sort of temp protection built in now.

 

[Egil Solberg]

I read last light where the amd cpu itself shuts down, granted the shutdown
temp is listed "outside" the operating spec, but it does say it shuts down

Intel CPUs shut down *all by themselves*. AMD CPUs require logic on
motherboard. Therefore the Intel solution is better.
AMD will follow Intel´s example and make the thermal protection
mobo-indepentent with their Opteron-line of CPUs.

 

[Neil]

I 've actually forgot to plug in my pump on my water cooling system a few
times till I started runnig it 24/7 and the sytems do shut down and this was
on kt333a and the newer NF2 boards/. I now use a power supply the new
vantec 400 watt that has a compimentry switched plug on the back that works
fine and control the on off of my eheim pump.


Neil

beleive he was asking if a fan quit working while sink was on.

The BIOS normally has "Fan fail alarm" - though not sure if that also
means shutdown if the situation continues.

The conventional under-CPU heat sensing OUGHT to be fast enough for
thermal protection if the fan fails but the heatsink is still
attached, since the heatsink provides thermal mass and some cooling
effect. A mostly closed, fine finned haetsink will be worse than a
more open design under these conditions.

The forewarning of fan fail that MIGHT be noted are:
1. Gets noisy, particularly the groan of a fan with bearing trouble
2. If you monitor speeds (and they aren't being varied automatically)
Speed is lower than normal, or varies beyond the usual measurement
flutter.

well its easy isnt it? best way to avoid that problem is..."Never turn
your/any rig on that dosent have a HSF on the cpu..." duh...

Hi folks,

I understand that the CPU will 'fry' within a few seconds if the PC is
switched on without the heatsink and fan fitted.

What is the situation if the heatsink and fan are fitted but say the
fan stops and only the heatsink is left to dissipate the heat. How
long before the CPU 'dies' ?

Are there any checks in place to stop the PC from starting if the fan
dies ?

Do any 'alarm' bells go off if it does happen to tell us to switch off
the PC immediately ?

Is there any 'forewarning' that the fan is about to die ? (similar to
the 'SMART' diagnostics for hard disks ?

(In case this is motherboard specific, the motherboard in question is
Asus A7N8X Deluxe V2)

What precautions can one take to avoid this scenario ?

TIA,
Arif

--
I may be dozzzy, but take the ZZZ's out to mail me
http://www.junkroom.freeserve.co.uk/jvc2080.htm - 2x2x24 CD-RW troubles

If you drop a cactus, don't try to catch it!