What is an Intel Core i7 720QM?
While there have been Core i7 laptops before, these have used desktop chips and been the size (and weight) of large paving slabs. The Core i7 Mobile
series brings three chips that are designed to be squeezed into a foldaway PC.
Kobalt has used the entry-level model for its G860 gaming laptop
, the Core i7-720QM, which has 6MB of Level 3 cache and a nominal frequency of 1.6GHz. The 820QM has 8MB of Level 3 cache and a nominal speed of 1.73GHz, while the 920XM Extreme Edition also has 8MB of Level 3 cache but a nominal frequency of 2GHz.
We say ‘nominal frequency’ because not only does the Core i7 Mobile have the usual SpeedStep technology to lower the multiplier (and therefore the overall frequency) when it’s not working hard, but there’s also Turbo Boost technology
to increase the multiplier when the CPU is working on single-, dual- or even eight-threaded applications.
We saw the 720QM in the Kobalt G860 clock itself at anything from 933MHz (with a 7x multiplier) to 2.79GHz (with a 21x multiplier). If you wanted proof that the gigahertz war was over, this is it – it’s all but pointless to talk about these CPUs in terms of a rated frequency.
The three new Core i7 Mobile CPUs are fairly similar
Kobalt's G860 is the first laptop we've seen to use an Intel Core i7 Mobile CPU
All of the new range of Core i7 Mobile CPUs are quad-core, all have Hyper-Threading (so can process eight threads in parallel), but while the 720QM and 820QM have a low TDP of 45W, the 920XM Extreme Edition has a TDP of 55W.
Apart from the differences in Level 3 cache and maximum Turbo Boost frequency, the three Core i7 Mobile CPUs are fairly similar. All three have a dual-channel memory controller and can address up to 8GB of memory.
As the chipset to which these ore i7 Mobile CPUs connect is the PM55, we know that they're based on the Lynnfield design
rather than the beefier Bloomfield core
Intel says that, based on orders of 1,000 units, the 720QM costs US$364 per CPU, the 820QM US$546 while the 920QM Extreme Edition costs US$1,054. We know which we'd buy...