It is not GT3 with units disabled
We had a chance to talk with a few people from Intel and one interesting thing that we managed to pick up is the fact that the Haswell graphics module will mean a different silicon, and as a matter a fact, a totally different chip.
From what we got from one of the graphics engineers we talked to, is that we can expect at least two chips, one featuring GT3 graphics and one with GT2. Intel plans to use GT3 graphics on H-line chips, while M-line processors come with the GT2 module.
In case is not clear and obvious, GT3 graphics on Haswell will be the faster one, offering some competitive results, close to Nvidia entry-level cards of 6th generation, with GT2 as a runner up.
There will be many graphics brands, especially in mobile space, as so far we saw Intel graphics 4000, 4600 for GT2 based processors and an indication of 5200 for some GT3 products.
We expect that there are quite a few transistors on the GT3 core and the fact that some H-line processors for mobile fit the 37, 47 and 57W TDP envelopes is impressive.
Let me underline that H-line processors will be quad-cores with GT3 only, while M-line will come in quad and dual flavours, but only with GT2 graphics.