Today we will be looking at the Core i5 661, one of four new Core i5 processors. The other models include the Core i5 650, 660 and 670. Based on this naming scheme the Core i5 661 doesn't seem to fit quite right. Furthermore, Intel will charge $196 for both the 660 and 661 processors, but we'll break it down for you so you can gain complete understanding of the new processor line-up being announced today.
But before delving into more detail there's a thing or two you will want to know about the new Core i5 600 CPUs. This new series is based on the 32nm Westmere die shrink of the Nehalem architecture and goes by the code-name Clarkdale. Of most relevance, all processors in the series feature a built-in GPU.
Obvious differences between the Core i5 660 and the 661 is that the latter doesn't support Intel's VT-d (Virtualization Technology for Directed I/O), vPro or Intel Trusted Execution Technology (TXT). The other key difference between the two is the GPU's clock speed. While the Core i5 661 operates its GPU at 900MHz, the other Core i5 600 series processors including the 660, use a GPU frequency of 733MHz. The reason for this distinction is unknown to us at this point, but that's the way Intel is playing it.
Therefore, for the first time ever it is possible to purchase a CPU that features a built-in GPU that is entirely separate from the chipset. This is known as a General-Purpose computation on Graphics Processing Units (GPGPU) and refers to the technique of using a GPU, which typically handles computation only for computer graphics, to perform computation in applications traditionally handled by the CPU.
The Clarkdale processors have another first time claim to make and that is to be the first processor series to be built using a 32nm (2nd Generation Hi-K) design process. This should help improve efficiency, allowing them to use less power and generate less heat than existing processors, such as those based on the Lynnfield (45nm) architecture.
Hardly surprising, Clarkdale processors will require new chipsets and motherboards to support the integrated graphics. These new chipsets include the Intel H55, H57 and Q57, while it is worth noting that the Clarkdale processors will work with existing P55 motherboards albeit losing the ability to use the integrated GPU.