Does TDP matters so much?

What would be the temperature of 10w TDP difference?

Lets say, 25W vs 35W. What would be the temperature difference? 5C? 10C? Anyone already did the test?

Cheers

 

You misunderstand the nature of TDP. It's just the design power at a specific point in the chip. Higher TDP typically translates to hotter components, but not in a straightforward way: temperature depends greatly on the cooling solution used in a specific laptop. Furthermore, the definitions of TDP are not the same across companies.

 

If I got a t9400 (35W) on a laptop, or a p8700 (25W) on the SAME laptop, what would be the temperature difference? Thats what i wanted to ask.

 

The answer here is that the temps would depend on if the laptop in question was built for the 35W part or the 25W part.

If built (optimally) for the higher wattage part - the temps would be the same at the same workload.

If built for the lower wattage part, the temps would be higher when the higher wattage part was installed - if/when the system was pushed to it's maximum. At idle/normal levels, the temps would be pretty much the same.

 

at 100% CPU utilization, the p8700 would be cooler. thats all the TDP rating will tell you(an actual engineer might be able to infer a LITTLE bit more).

if you want to know the temperature difference, go benchmark it yourself. That will be the only way to know.

 

Generic User #2 and tiller hit it pretty well already.

More things matter than just TDP; clockspeed, stepping, and voltage play a huge part despite parts having similar TDPs (ie: a T9900 will run hotter than a T8100 despite having 35W TDP each).

But in short, when I switched from my P8400 (2.26Ghz 25W) to an E8335 (2.93Ghz 35W), my temps went up about 15C at load.
At idle is not as comparable because the E8335 doesn't have DFFS, which downclocks the FSB when possible, so it runs hotter naturally (5-10C hotter). 45W Extreme CPUs are known to run as cool or cooler than 25W cpus at load depending on the stepping, so again, idle temps are really moot.
At OC my temps went up by as much as 20C, but I am also able to overclock by a higher % than I could previously.

 

You are saying that X9100 will run as cool as p9700? or cooler?

 

It depends on the chip too, typically the fastest chips are chosen for the x9100 series, they also tend to be the leakiest, but if it's a golden chip that's just right it could be fast and efficient, in which case it could be.

 

It also depends on the age/era of the CPU. With SB a 45W quad core uses nearly the same amount of power as a 35W dual core when idle, but Core 2 didn't have power gating.

 

I'm saying that depending on the stepping, there might be circumstances where a P series CPU can be warmer than a T or X series CPU, mainly at idle. It really varies depending on CPU vs CPU.

I think a better comparison would be an early-stepping P8400 vs a late-stepping X9100. The P9700 was released late and already uses the same stepping as some X9100s (E0)

 

I'm asking cause I want to upgrade my p7350 to something decent. I'm looking at p9700 cause my laptop is already a hot head. Your comment made me think that maybe X9100 is better choice.

 

Generally, the faster the CPU, the hotter it will run. Then again, have you tried cleaning your laptop? Also, a cheaper alternative would be repasting your thermal compound and/or a cooling dock (or even something that elevates your laptop).

 

I already have a cooling pad. I cleaned laptop inside today, around 2 hours of taking it apart only to find out that internally it's strangely very clean! Took out few dust specks from the cooler, I also looked at the thermal paste and it looks intact. I'm still running 50grad Celsius on idle (both gpu and cpu). Assembly reaches 40 on idle.

I also undervolted cpu, so that it runs on lowest possible value 0.925

I'm running out of options very fast...

but I'd love to upgrade cpu

 

When you say the thermal paste looks intact, you did put fresh paste on when you took the cooler off right?

 

ehm, no, I need to buy it first... next week going to grab it. It's not so easy to buy this things in italy.

 

TDP is the thermal envelope notebook manufacturers use to design a cooling system.

If Intel recommends a 30w TDP, it means the chip is capable of creating 30w of heat so manufacturers will need to create a cooling setup that will allow the chip to run safelty without overheating and downclocking.

 

Do that first!

You may want to ask if any 'free' tubes are still available on this thread:

See:
http://forum.notebookreview.com/har...c-diamond-24-giveaway-reliability-survey.html



Also, when you clean out your system - do you clean the fan blades too (with a Q-Tip?) - did you (possibly) destroy any cooling pads used in your notebook? Once you disassemble your system - you should be putting new thermal paste and new thermal pads (if they were used originally) and not simply re-assembling the notebook with the old parts.

 

I will grab thermal pads too, there were allot of them used througout the heat transmitter arms. I was told there are different thickness ones, so I had to look first, mine seemed to have 2mm pads.

man I can't believe I did 3 hour work for nothing, I've to do it again tomorrow ))

 

No, it is not 3 hours of work for nothing: this is called learning.

Bet you won't make this mistake again.

 

heatpipes...? lol

 

No, we're talking about the thermal pads.

 

I'd go with the P9700. I have the p8600 which is pretty much the same except slightly lower clock and even with my laptops notoriously bad cooling, I was able to get 36* idle with it and 65* load.

The P series also has SLFM which allows you to go down to 0.8750 volts which really does make a difference. Two of my multipliers are still as low as they'll go (0.8750, one of them being 1.6ghz, the other being 0.8). I'm probably going to do a pinmod to see how low I can push the lower multipliers. I'm hoping that when I get round to properly taking care of my cooling, I should be able to pull off sub 35* idle temps.

 

I think I have a great example here guys. I upgraded from T6600 35W to E8435 55W processor.
temps on t6500 `40C `65C
temps on E8435 `45C/55C `81/85C (two cores have different idle temps)
Also should mention that its at 1.075volts instead of default 1.250volts.
at 1.250volts E8435 load temps would reach over 100C and shut down immediately.

 

its just that he said heat transmitter ARMS. the only arm-like things that have to do with heat that i could think of were heat pipes lol.

 

Seems like you should reapply the thermal paste, 10°C difference between the idle temps of the cores is way off.

 

I have an E series CPU and the core temps differ by 5-10C, the temp sensors from intel which should just be taken kind of loosely.

 

I did it bunch of times. I wish I could tighten the heatsink a little further than it is now. It would be much cooler.