Can someone explain TDP to me? Went from Dual to Quad and temps dropped

[pantsaregood]

The ice cubes won't break 0 C without melting, yes. I don't really see how that's a trick question.

 

[reallyscrued]

<snip>

AMD basically assigns this TDP based on the highest member of the family tree and the lesser models typically run somewhat lower. Just because they state a chip runs 80W or 95W doesn't mean it runs that constantly. The TDP is more of a guide to the OEM system builders out there (think Dell, HP, etc) to know the maximum heat they will have to dissipate from a given CPU at stock settings under load.

I just read on that Wikipedia.

This seems like most plausible reasoning now.

The X2 550 is a black edition which is probably the hottest rated Dual Core Phenom II AMD offered and the X3 830 was probably the coolest Quad PII AMD rated.

It still seems odd to me a Quad wouldn't need significantly more efficient cooling than a Dual but I guess there's a whole lot more than meets the eye.

 

[2is]

15 ice cubes will cool faster because of the increased surface area.

 

[Ferzerp]

Your ice cube question should be lumps of metal or the like. Ice cubes will have a phase change in the mix, making it even more confusing!

 

[pantsaregood]

The CPU being a "Black Edition" has absolutely no bearing on the CPU's heat production.

There is more to a CPU than its core count. A large portion of the Phenom II die is covered by L3 cache, a memory controller, and HT links. On any model, be it X2 or X6, these are the same.

 

[reallyscrued]

The CPU being a "Black Edition" has absolutely no bearing on the CPU's heat production.

There is more to a CPU than its core count. A large portion of the Phenom II die is covered by L3 cache, a memory controller, and HT links. On any model, be it X2 or X6, these are the same.

What I meant was that it being branded a 'black edition' but still a dual core probably puts it at the top tier of the "80 watt cpu" tree while the lowly stock 830 would likely be at the bottom of the 95 watt quad core tier.

 

[KingFatty]

The ice cubes won't break 0 C without melting, yes. I don't really see how that's a trick question.

Well my suggestion of trick question is because of the melting/phase change, because that's totally different than the previous examples where you have a big thing at a warm temperature, and a small thing at a very high temperature.

With ice cubes, their initial temperature (e.g., the warm temperature of -100 degrees C, and the very high temperature of -10 degrees C) might be rendered irrelevant by the melting/phase change. Sorry I didn't do the math, but my point is that if the initial temperatures are irrelevant, then the question collapses down to merely looking at the number of ice cubes regardless of their temperature. if so, the question collapses down to: which is more, 1 or 15?

Put another way, warming one ice cube from -100 C to 0 C is an almost negligible amount of energy compared to how much is needed to melt that same ice cube. Similar argument for warming 15 ice cubes from -10 C to 0 C. Especially compared to a tub of warm water, that tub won't really "see" the effect of changing the temperature of the ice cubes, but will start to see the effect of melting the ice cubes from ice to water.

 

[Haserath]

When they're both at stock, the quad should be pumping out more heat than the dual core, which does make the heatsink hotter.

The quad has a lower heat density overall than the dual core though, so even though the heatsink is warmer, it must be able to handle the higher TDP with enough efficiency to keep them about even. Overclock the quad to 3.1 and keep the same voltage between them; you should see at least some increase in the quads temps then since the heatsink has more load on it.

I've also been thinking the heatspreader probably does its job very nicely. The solder is the best contact interface between the die and metal, so the die could transfer heat much more quickly to the heatspreader than to a heatsink with paste. So it does just what its called, spreads the heat out to transfer faster to the heatsink.

 

[Edgemeal]

Scenario:

I had a Phenom II X2 550 BE (Callisto, or Deneb with two defective cores) clocked at 3.7 Ghz being fed 1.45 volts. Says 80 Watt TDP.

Small FFT test - Maxed out 53 Degree Celsius on stock hs/f

I doubt that stock cooler kept that CPU at 53C unless, A) the room was very cold, B) your reading the core temps which are mostly bogus on AMDs, you should be reading the single temp reading.

and C) Was that X2-550 a C2 revision? According to AMDs errata docs for the phenom family the X2-550(C2) is marked as not returning a correct CPU temp.

 

[muk1604]

ok

 

[Puppies04]

According to this thread:

http://www.xtremesystems.org/forums/showthread.php?182095-Naked-Phenom/page2

The heatspreader is soldered on.

And removing it doesn't result in lower temps.


I'd say the heatspreader does its job.

I would love to know what point you are trying to make here, go back and read my post then let me know what it is exactly you are talking about.