Intel has officially announced its long awaited "Clarksfield" quad-core notebook CPU, with the ability to automatically overclock to 3.2GHz.
The new Mobile quad-core i7 is based on the Nehalem microarchitecture, and comes in clock speeds up to 2.0GHz. However, if any of the four cores is not being fully utilised, the CPU can crank up the active core(s) to anywhere up to 3.2GHz.
Intel mobility chief Mooly Eden holding one of the chips up:
Those speeds are on the pricey "Extreme" Core i7-920XM version of the CPU. The more realistically priced version, i7-8200M runs at 1.73GHz and ramps up to 3.06GHz. An even cheaper version, the i7-7200M, runs at 1.6GHz and boosts up to 2.8GHz.
Intel will make a Windows desktop widget available that updates every two seconds and shows how fast your i7 CPU is currently running.
Shared L3 cache is another key feature of the chips: the Extreme and the i7-8200M both have 8MB of it, while the cheaper i7-7200M has 6MB. The L3 cache is shared among all four CPU cores and is "fully inclusive", which means that each processor core's L1 and L2 cache is duplicated in the L3 shared cache. The benefit of this is that if a core is sleeping and another core is running in Turbo mode, the processor doesn't have to wake up the sleeping core in order to access something in its cache. The result? Lower power consumption and more time spent in turbo mode.
Of course, current Core 2 Duo CPUs from Intel run as fast as 3.06GHz full time, but Core 2 Duo CPUs do not support Hyperthreading so you only get two CPUs at any time. The quad-core i7 notebook CPU does support it, so even if it scales down to one core in order to run at the top speed of 3.2GHz, you'll still have two effective cores available to the CPU (albeit with less real processing power).
In fact, given that four cores are available, with Hyperthreading, eight effective cores are made available to the OS -- meaning that if you run many apps at once, the OS can distribute them round the cores without the system slowing down.
Referring to the Turbo technology that can boost the core speed, Intel's mobility chief, Mooly Eden, said, "We believe this is the best quad core design on the market … some quad-core CPUs without Turbo technology might run software slower than a faster dual-core CPU."
The chips also have an integrated memory controller, providing much faster memory connectivity than a separate controller could provide. Intel claims it provides 2.9x faster memory performance -- particularly important in terms of accessing the very high speed cache on the chip.
Pictured below, the kinds of performance boosts Intel claims we will see over its previous quad-core mobile chips. (It's worth considering, of course, that most people using 15" notebooks are still using dual core CPUs, so the boost of moving from dual to quad core could be even more.)
Intel also previewed chips codenamed "Arrandale" which will combine a "Westmere" generation 32nm dual-core CPU with a 45nm GPU in the same package. On your motherboard it will look like one chip, but it will allow power to be dynamically allocated to the CPU cores or GPU, depending on which is the most in demand at the time.
"We can look at the GPU and the CPU and if either one is not using the full power, we will instantly jump that over to the other side," Eden said. "It gets more complicated, but it's beautiful."
Pictured below, Intel thermal imaging showing power being shunted from the CPU to the GPU.
Core i7 quad-core notebooks on display
The HP Envy:
A Lenovo:
Toshiba Qosmio:
