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Haswell Test: Intel Core i7-4770K and i5-4670K

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Dennis Bode

Page 3: The Haswell Architecture - the GT3 graphics

Intel's goal is to make smaller graphics solutions obsolete by using integrated graphics - you can not keep up with a GTX 780 or similar transistor monsters, and Intel is well aware of this. Instead, they want to create the opportunity to realize good graphics to watch videos, play games or to control several displays, and provide this for smaller systems, Ultrabooks or cheap computer systems. In recent years, they have therefore been revising the graphics continuously - and have reached a really good level.

Haswell graphics: GT3 improvements

The graphics of Intel's Haswell models will be available in four configurations: for notebooks and the i7-4770R, they provide the "GT3" - and "GT3e" versions. These two variants differ by an embedded DRAM, which Intel has placed on the CPU. Embedded DRAM is Intel's name for the graphic version Iris Pro 5200. If only the faster option is being used, but without the extra memory, Intel calls the package "Iris 5100". Power-saving models, featuring a few execution units less, bear the name HD Graphics 5000.

The desktop sector however will only see the GT2. Its has less execution units and also comes without Embedded DRAM. Intel will sell these graphics solutions with the names of HD 4600, 4400 and 4200. A stripped down GT1 version will be available for cheap CPUs:

Naming of the Intel graphics
Graphics solutionPC clientsWorkstation / Server
GT3e Iris Intel Pro 5200 -
GT3 (28W) Intel Iris 5100 -
GT3 (15W) Intel HD Graphics5000 -
GT2 Intel HD Graphics
4600, 4400, 4200
Intel HD Graphics
P4700, P4600
GT1 Intel HD Graphics -

We have summarized the technical features of the new Intel graphics in the following table. Intel HD Graphics 4000 and 2500 is for Ivy Bridge models, the HD Graphics 3000/2000 for older Sandy Bridge models. We listed also Intel HD Graphics 5x00, even if they are to be found only in the notebook sector:

Comparison of CPU Graphics
Graphics coreIntel HD Graphics 5000
(GT3, for desktop i7-4770R only)
Intel HD Graphics 4600
(GT2)
Intel HD Graphics 4000Intel HD Graphics 2500Intel HD Graphics 3000/2000
Unified Shader yes yes yes yes yes
Number of Execution Units 40 20 16 6 12/6
Media Processing
(Quick Sync / Clear Video)
yes, new Video Quality Engine yes, new Video Quality Engine yes, improved yes, improved yes
OS optimizations Windows 7 and 8 Windows 7 and 8 Windows 7 and 8 Windows 7 and 8 for Windows 7, Vista, XP
Frequency maximum of 1300 MHz maximum of 1250 MHz maximum of 1350 MHz
(Currently: 1150 MHz)
maximum of 1350 MHz maximum of 1350 MHz
DirectX support in hardware DX11.1 DX11.1 DX11 DX11 DX10.1
OpenCL 1.1 OpenCL 1.2 OpenCL 1.2 CPU / GPU CPU / GPU CPU only
OpenGL support OpenGL 4.0 OpenGL 4.0 OpenGL 3.1 OpenGL 3.1 OpenGL 3.0
Shader Model SM 4.1 SM 4.1
Dynamic Frequency Scaling yes yes yes yes yes
Maximum Resolution 3840x2160 (DP) 3840x2160 (DP) 2560x1600 2560x1600 2560x1600
HDMI Support 1.4 with 3D 1.4 with 3D 1.4 with 3D 1.4 with 3D 1.4 with 3D
Number of Displays 3 (see below) 3 (see below) 3 3 2
Intel WiDi 4.1 4.1 3.0 3.0 2.1

Technically, Intel has improved the features: DirectX11.1 support, as is OpenCL 1.2 in hardware (for example, for filters in Adobe Premiere Pro) as well as OpenGL 4.0. In addition, Intel has increased the bandwidth of display ports, enabling higher resolutions, and up to three screens can be connected as a Collage Display. We listed below which displays can be used. If you switch to 24 Hz, even 4Kx2K videos can be seen on a suitable display.

Due to the large number of execution units, there are improvements in the usual video features: Intel Quick Sync Video Technology is faster, de-and encoding works faster, too. As an additional part of the Quick Sync Video Technology, there is a Quality Video Engine which will unshake videos and can correct colors. In addition, Intel has also integrated a faster JPEG & MPEG decoding (eg webcam).

In order to feed the execution units with data at a faster rate, Intel has revamped the architecture: the number fixed-function units in the 3D pipeline has been doubled, the command units have been provided with a resource streamer,  thus rendering 3D scenes faster.

The structure of the new graphics are shown in the following slideshow. Intel uses the same structure for GT2/GT1 and GT3; GT3 only features a higher number of execution units, and thus also larger caches and buffers are used. But the size of the on-chip caches is still a mystery.

Intel IDF 2013
At the Intel IDF in April 2013 in Beijing Intel showed the structure of the GT1/2/3-GPUs.

Embedded DRAM on the CPU

This aspect is of course exciting - but actually unimportant in the desktop segment, since Intel still does not sell CPUs in socket 1150 with embedded DRAM. For the GT3e models, this technique is provided, even though it grants a speed advantage not only in the notebook sector, but also in the desktop sector.

In the top models Iris Pro, Intel integrated 128 MB cache on the CPU core, which acts effectively as a level-4 cache. The execution units will use it, as will the graphics, but also the cores themselves. Since it is connected with 512 bit interface, this memory is extremely fast, which just helps to make for a significant performance increase, since the data does not need to be written in the much slower main memory. But the disadvantage of this solution is the high price and the additional waste heat, which is why Intel will probably not provide desktop models with this technology.

Intel implemented the EDRAM next to the Haswell CPU on the chip. In essence, this is a multi-chip package, as it has already been implemented earlier with the first dual-core CPUs or the first integration of the Northbridge to the CPU.

Display connectivity

Intel Haswell advertises the ability to run multiple monitors in collage mode. Effectively, you can - depending on the connections on the motherboard - use up to three monitors. It is even possible to display a 4Kx2K resolution. Since the connectivity depends significantly on the ports provided, we have summarized the supported by Intel in the following table:

Connectivity and display resolutions
Screen 1Display 2Display 3Maximum Resolution
Screen 1
Maximum Resolution
Display 2
Maximum Resolution
Display 3
HDMI HDMI DP 4096x2304 @ 24 Hz
2560x1600 @ 60 Hz
3840x2160 @ 60 Hz
DVI DVI DP 1920x1200 @ 60 Hz 3840x2160 @ 60 Hz
DP DP DP 3840x2160 @ 60 Hz
VGA DP HDMI 1920x1200 @ 60 Hz 3840x2160 @ 60 Hz 4096x2304 @ 24 Hz
2560x1600 @ 60 Hz
eDP DP HDMI 3840x2160 @ 60 Hz 3840x2160 @ 60 Hz 4096x2304 @ 24 Hz
2560x1600 @ 60 Hz
eDP DP DP 3840x2160 @ 60 Hz 3840x2160 @ 60 Hz
eDP HDMI HDMI 3840x2160 @ 60 Hz 4096x2304 @ 24 Hz
2560x1600 @ 60 Hz

Any motherboard can provide the following maximum connections:

  • two HDMI
  • two DVI
  • one HDMI and one DVI
  • up to three DisplayPort
  • a VGA
  • a eDP

The use of the new display port 1.2 standard enables you to use DP monitors by daisy-chaining them. Intel provides twice the bandwidth (compared to DP1.1). With the ability to connect three displays, this will eliminate the need for many users to opt for a dedicated graphics solution if that power is not needed. The flexibility of Intel's onboard graphics here is perfectly adequate - even for 4K2K or the like.

It is also interesting that Intel allows for operation of an onboard graphics at the same time with the dedicated graphics in a PCIe x16 slot. This way, the user can connect two monitors to the PCIe solution, and up to two more on the onboard graphics. Only drag-and-drop between monitors of different graphics solutions will not be possible.

Displays can also be connected via WiDi 4.1, if the mainboard provides this option.