I must have put a little less than half of the syringe, by asking a medium ball in the middle of the processor as suggested. No trouble ejecting the moderately flexible pasty substance.
After full dusting of the entire system (motherboard, rads, ventilos, ...), at rest, I have not noticed any improvement, but be careful anyway, I changed my processor, and I spend 2 6 to 3.5GHz: it is at 35-40 degrees (25 to the cold start, 35 degrees in the housing that is cooled by the CPU fan which ejects hot air at the rear of the housing) but it is a mini PC with a priority system Shuttle ICE with 4 heat pipes, small heatsink and small fan, so very limited cooling.
This is not necessarily better than the old dough over 5 years on the i7 920, but it may also be that it is a less correct installation on my part (plate less discount, wrong dosage of the paste, difficult evaluate). Parcontre, 100% CPU, it does not exceed 75 degrees and the fan did not even flinch. This is also due to the CPU cooler to the base (32nm against 45, the latest model of LGA 1366). At full capacity, the fan dissipates up to 10 degrees, which at least proves that dough conducts heat well.
I recommend it all the same, because it is the latest technology (nano) in thermal paste, and one of the best pros selons tests (pro I'm not!).
At this price, you get to 2-4 replacements dough at least!