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The Report of My Thermal Death Have Been...
A reader writes "Not too long ago, Tom's Hardware posted a video of the grisly events that take place when the heatsink is removed on an AMD Athlon MP 1.2GHz in an attempt to show that the chip has inadequate thermal protection unlike the Pentium 4. Apparently, this is not the case. This new video, which looks like was done by AMD, shows the system continuing to work when the heatsink is removed. Even 9 minutes of Quake3 without the fan operating wasn't enough to destroy the processor. So who is right? It's in AMD's best interest to show that their product doesn't disintigrate under extreme conditions. " Update: 10/30 14:11 GMT by H : Note that it was Terry 'quad3d' Wang that actually did the video - not AMDZone.
here with videos on the 5th or 6th page.
All this shows is a motherboard with sufficent onboard temperature monitoring, shutting down because the CPU is over heating. It has nothing to do with the CPU having any sort of built in temperature throttle like the P4 has (or even the 68040 had). Tom's Hardware and this video are showing two completely different and seperate things. One shows how a motherboard reacts in order to save an amd cpu (this current video), and the other shows what happens if the cpu is left to cope with a heat problem on its own (Tom's tests) without the motherboard stepping in to rescue it.
/. just doesn't care some days... or maybe its just on slow days ;).
I wish people would at least FILTER some of these posts. Its seems that
It's windows media video. On linux, play it with mplayer.
No, Tom's results show that when the heatsink is removed, the blue smoke gets out. The AMD video shows the machine shutting itself down. The differences is that the Intel processors simply slow way down, but keep running.
AMD's test is apparantly usings a thermal shutdown sensor, which shuts the power down when the CPU gets too hot. Not all motherboards have those, and they can be disabled in software. Intel processors apparantly have a similar function built-in.
I work for a local computer shop, and although we are no Dell or Gateway, we've seen a lot of weird hardware stuff over the years.
And the fact of the matter is that AMD CPUs can really burn up just like in Tom's Video.
We've seen more than once, a customer coming back with what he said was a defective AMD CPU, and when we check the CPU, we could see the adhesive barcode that we put on the underside of each, partially burned out !
And don't get me started on the damn fragility of those AMD CPU, we've got dozens of them broken because some guy slipped when installing a fan on them.
Murphy
Of course AMD's test worked, they used a relatively expensive thermal diode that is probably used on high-end boards. Are these used on the majority of boards? no.
2 405.
Consequently, i see their test as wrong, as proving that they can have the reliability that people expect, but since they didn't put the diode internally, they cannot claim that all systems will have this reliability feature. in fact, most won't.
The spec sheet for the thermal diode shows that the thermal diode they used typically has a response of 70ms. see: http://dbserv.maxim-ic.com/quick_view2.cfm?qv_pk=
but, at 85 cents each, nobody uses them. the cheap diodes are probably 10 cents each, or less.
I recently (two months ago) bought myself a Athlon 1.4 Ghz CPU and because the fan that was supplied with it was so noisly, I switched it for another fan. However, I was careless and didn't mount the heatsink/fan properly onto the CPU (basically they weren't touching).
Let me assure you that the Athlon 1.4 Ghz is more than capable of destroying itself within 5 seconds if it doesn't have adequate cooling.
I am now Aus$400 poorer and a little more careful.
The video demonstrates an AthlonXP processor. Tom was testing the "pre-XP" version. This leads to a VERY unfair comparison...Tom directly mentions that the XP will use the same core that the dual-capable Athlons do...this core does have built in temperature management. The Pre-XP processors DID NOT and WOULD FRY if left unhelped. This doesn't demonstrate that Tom's test was wrong or his results invalid...this shows that AMD knows they screwed up but were at least smart enough to fix the problem in the next significant rev of the chip (though that doesn't fix the situation for those of us with Pre-XP chips)
The Intel chip is still better, because the mobo didn't matter. The chip underclocked itself, or shut itself down, without any additional assistance. This is superior to any sort of motherboard dependency.
When Tom tested Atlon 1800 XP vs Intel 2 GHz he used lots of different benchmarks, including quake, unreal torunament, dronez, evolva, 3DMark 2000, 3DMark 2001, Sisoft Sandra, and Cinema4D.
Seems very thorough to me. Also he concluded the Athlon was better than then Pentium.
Tom did test the MP version of the Athlon which has the same core as the XP (palomino). He also tested a pre-XP version both gave very similar results.
I suspect the problem may be that the motherboard Tom used did not properly support the Palomino core's thermal diode protection. This is not a problem with intel cpus as they have all the required saftey circuitry on die.
But Tom was testing on a system that DID NOT SUPPORT PowerNow. Yes. It had support for reading the thermal diode. But, IIRC, simple support for reading the diode doesn't equate to PowerNow support.
So yeah. If you run on an older system without PowerNow, it's the same as running an Athlon without a thermistor.
On a setup that actually supports the thermistor, the system will shut down in time.
Chas - The one, the only.
THANK GOD!!!
It's also probable that the Athlon XP is of a different stepping than the Athlon MP, and the 1 degree/s limitation was remedied (or it was a siemens board problem that they were unwilling to accept responsibility for).
I used up all my sick days, so I'm calling in dead.
You're forgetting one very important detail. The CPU presented in that little video clip is the Athlon MP, the new Palomino core that supports SMP. I wouldn't be surprised at all to find that AMD made their new MP processors resistant to heatsink/fan failure, following on the heels of Intel's P4.
The processor that Tom Pabst had fried is an older model, using the T-Bird core. It is only fair to assume that the old Athlons didn't have this overheat protection built in (which becomes obvious for all of us who have fallen victim to those stupid rubber spacers on early heatsinks).
-Billco, Fnarg.com