T6500 vs P8700 vs T9400

How much performance increase of P8700 2.53ghz over T6500 2.1ghz? Will I notice the difference in the day to day use?

Secondly, which processor is better; P8700 or T9400 as both have 2.53ghz?

Thanks

 

For what purpose and programs and price?

For P8700 vs T9400, if you want the speed, just get the cheaper one or the T9400 if the price difference is very little, because you can (try) undervolt for the difference in heat produced.

If you're just a casual user (eg web browsing, watching videos, casual gamer*) you will not notice any difference in speed. My sister has a 2.0GHz older C2D and I have a 2.4GHz latest gen C2D and there is no difference in general user experience.

 

I'm assuming you will have the processor in a laptop, so for this reason I'd suggest going for the P8700 as it has a lower TDP (25 watts I believe). Simply put, it will get you better battery life.

 

The P8700 has a slightly lower voltage and half the cache disabled (it should still be physically there as the core size is the same according to intel ark).


a. if you don't need the extra CPU power (and you probably don't) and the prices of the faster cpus (t9400 and p8700) are ridiculous, then just get the t6500.

b. if the prices of the t9400 and p8700 are the same, get the t9400 and then undervolt.

c. if the p8700 is significantly cheaper than the t9400, just get that then.

 

P8x00 have that half of the cache disabled. Die harvesting =)

 

True.

And if you use undervolting the T6500 will give similar battery life as P8700.

 

Thank you guys for the reply. The reason I ask T6500 Vs T8700 is due to which Asus specs that I gonna buy. If you could help me to decide this I would greatly apprecite it.

http://forum.notebookreview.com/showthread.php?t=415263

 

None of these chips have any cache disabled. They uses different dies. I also don't buy the power usage difference based on some arbitrary "TDP" figure that may or not have any relation to power consumption.

 

The die size on any website I see has then all as 107mm2.

 

Intel produces their current penryns on two dies, one with 6MB of cache called the E0, and one with 3MB of cache called the R0. The 107mm^2 figure you mention is only for the E0 die.

 

What's the size of the other one (R0)? Though I do now see that there are two different cores (eBay images).. Also, so no core harvesting?

Regarding power for the P-series processors, it's a slightly lower voltage, but half the amount of cache, so for how much less resistance I would never know..

 

The R0 is 82mm^2. The higher end P series processors have the full 6MB of cache. If you want proof that the TDP is a bunch of bologna, look at the Celeron 900. It is an R0 stepping processor at 2.2Ghz with 2GB of cache disabled and one of the cores disabled. Intel gives this a TDP of 35w. It would use less than half the power of a 2.2Ghz dual core, yet its TDP is 25% higher than the 2.8Ghz 6MB cache P9700's TDP of 28w.

 

Does the Celeron 900 clock down like the other mobile core 2 processors?

 

There is no on the fly multiplier or voltage control on the Celeron so it only does FSB throttling. Either way it has no bearing on TDP, as TDP is the maximum amount of thermal dissipation the cooling system may be required to do, so we are talking full load at the highest clockspeed.

 

hmm.. I see. For some reason I was thinking that Intel's datasheets gave out as typical power consumption and not maximum.