Testing the 27 "iMac" Thunderbolt - part II

The presence of two Thunderbolt ports used to connect the iMac 27 "to two external displays. You'll have no problem to connect two Apple Cinema Display 27": Use two mini-Display Port cable (same connector as the Thunderbolt), and any ... work of 81 inches diagonally. If you use a screen of another brand or a former Apple screen, you will need an adapter: your adapter VGA, DVI, HDMI to Mini Display Port working perfectly. The only problem will come from screens 30 "you should use a dual-link adapter, an active housing costing hundreds of Euros.

Otherwise, the ports are used to little Thunderbolt: devices using this new standard, although promising, will not arrive until mid-summer. Intended primarily for professionals, promises to be cost prohibitive and limited uses for the moment, the interest of this new connector is limited to the general public.

This is not the case for other race horses of the new iMac. The processor is an Intel Core i7-2600, the fastest second-generation Core i7. It has four physical cores, identified as eight logical cores (hyperthreading) clocked at 3.4 GHz. When an application does not use all cores but needs power, the processor can disable cores dynamically to increase the frequency of the remaining cores: it can go up to 3.8 GHz on a heart (Turbo Boost). With all reasonable thermal envelopes in this range, 95 W is worth mention (32 nm etching).

(Cont.)

Mac Book Pro 13 "Core i7: The Turbo Boost function well

The 2.7 GHz Core i7-2620m team that the Mac Book Pro 13 "high-end mobile chip with the highest frequency available in the Intel catalog. It may even reach 3.4 GHz on a heart through the turbo boost, but Apple has apparently it off this feature to avoid overheating.

The Cupertino Company is yet to promote this function on the product page of Mac Book Pro, clearly indicating the frequency of 3.4 GHz that only the Core i7-2620m can be achieved in the current range. PC Pro has never yet managed to achieve this frequency in these tests, the processor remains hopelessly nailed to 2.7 GHz. Core i7-2720QM Mac Book Pro 17 "has no trouble reaching its maximum frequency of 3 GHz, so its four cores are at 95 degrees.

That's about the same temperature reached by the two cores of the Core i7-2620m Mac Book Pro 13 "at full speed to 2 GHz. This temperature is certainly high, but rather common, however, can only imagine the Turbo Boost, the processor could blithely exceed 100 °, temperatures this time potentially problematic. The English site therefore advances the hypothesis that Apple has disabled the Turbo Boost on the chip to avoid overheating. Notebook Journal (via) confirms this hypothesis: their copy is even temporarily increased to 798 MHz time to control its temperature.

Even without turbo boost, the Mac Book Pro 13 "Core i7 is a very fast machine. The question is whether Apple disables the default Turbo Boost, or if Mac OS X disables the fly: it will be difficult to know, rise in mean temperature rise mechanically. Having ourselves a Mac Book Pro 13 "Core i7 at our disposal, we will try to verify this behavior: we will update this article accordingly.

[UPDATE] Our own tests show that the Turbo Boost is indeed active on the Core i7-2620m Mac Book Pro 13 ". On two hearts, the incidence rises to 3.19 GHz (multi-core optimized implementation), so that it goes up to 3.33 GHz on a single heart (non-optimized implementation; Turbo Boost 2.0 is supposed to extend the "boost" Yet, we observe that the frequency goes down enough quickly, in very small increments (Intel explained that Core i7-2620m had 7 frequency ranges between 2.7 and 3.4 GHz).

The falling speed of the Turbo Boost seems to be correlated to temperature: the "boost" is much better during the first tests (when the processor runs at about 80 °) during the following (the processor then proceeds to over 90 °, with a peak at 97 °). It seems that Mac OS X and / or processor finely monitorent frequency to avoid overheating: it is again a function of Turbo Boost 2.0. Even in influencing the speed of the fans for the processor to overheat (remaining under the 110 ° measure), we observed no deactivation of cores or drastic fall frequency to avoid overheating.

In short, it seems that this processor is behaving as it should, with a much finer granularity of the "boost". PC Pro Notebook Journal as a tool used by Intel under Windows to test frequency: perhaps he is assigned a bug, or maybe the management of the Turbo Boost this particular model of processor is different ( or faulty) on this platform.