Graphics Core Versions
When we discussed architecture and major features, we spoke about two versions of the new Intel HD Graphics (version 2000 and version 3000) at the same time. In fact, these two modifications have dramatically different performance. And the primary reason for that is Intel decision to differentiate them not only by clock frequency, but also by the number of execution units. This is the major distinguishing feature between Intel HD Graphics 2000 and 3000: the top model has twelve execution units, while the junior model has only six. So, the peak performance of the top model may be at times twice the performance of the junior model.
We totally understand when Intel’s desire to separate the graphics corer targeted for different markets is coming from. Especially, since they intend to use three types of semiconductor dies in their Sandy Bridge processors: a quad-core and dual-core die with a fully-functional graphics core or a dual-core die with limited-functionality graphics. However, the way they position Intel HD Graphics 2000 and 3000 is a little confusing.
The general rule is the following: all mobile Sandy Bridge modifications are equipped with the top model - Intel HD Graphics 3000, while the desktop Sandy Bridge modifications receive a slower Intel HD Graphics 2000 with a few exceptions. These exceptions are Intel K-series processors for overclockers and enthusiasts. Just like their mobile brothers, these CPUs can boast a high-performance Intel HD Graphics 3000 core.
It is quite logical that they would want to use a faster graphics core modification in mobile CPUs. Integrated graphics is needed in notebooks, and even if they are equipped with a stand-alone graphics card the manufacturers retain the option to switch to more energy-efficient graphics core integrated into the processor, which will now be fit to handle more situations. However, it is at least strange to deprive almost all desktop users of the Intel HD Graphics 3000 accelerator. High-performance integrated graphics may come in very handy in desktops, too. But according to Intel, even the slow HD Graphics 2000 will do the job just fine, even though the faster modification of this graphics core could easily replace an entry-level graphics card. And it is even more surprising to see that Intel integrated their fastest HD Graphics 3000 modification into the Core i5-2500K and Core i7-2600K processors that do not need it at all. These CPUs are positioned for computer enthusiasts, who will never use integrated graphics merely because the Intel H67 chipset supporting it doesn’t offer any overclocking-friendly options at all.
The reasons behind this decision may be coming from the fact that they believe their HD Graphics 3000 is fast enough only for notebooks, because they tend to have lower screen resolution than desktop monitors. And since they do not think the performance of any integrated graphics core is high enough for comfortable work in desktop 3D applications, they modestly offer a junior graphics core in desktop CPUs. That could definitely be the case. But why would they put a high-performance graphics core into their Core i5-2500K and Core i7-2600K processors, while most users would totally understand if there were none? I can’t answer that.
Besides using graphics cores with different number of execution units in different Sandy bridge processors, Intel also resorted to an old time-tested trick: clock speed differentiation. Different processor models may have graphics cores working at different clock frequencies. However, now Intel HD Graphics frequency is determined strictly by the thermal envelope, instead of being a justification for market positioning.
The table below contains the general info about the Intel HD Graphics modifications integrated into second generation Core processors. Note that we have two frequencies for each graphics core: turbo-frequency at which the graphics core works in most cases, and nominal frequency down to which the graphics core may slow when the computational CPU cores are heavily loaded with work.