Intel HD 4600: game tests of desktop Haswell’s integrated graphic card
As soon as Haswell was released, we gave you a detailed article on new features of its architecture, as well as the test of two processors: Core i5-4670K and i7-4770K. However, this review didn't include Haswell's integrated graphic card; it was just a set of CPU tests. In games, these new Core processors were assisted by GeForce GTX 680 – a powerful discrete graphic card.
Unfortunately, Intel didn't give journalists any of the two-core Haswell models; we also didn't have a chance to test one of the processors soldered on to a motherboard (Core i7-4770R etc.) with Intel's most powerful GPU: Iris Pro 5200 (GT3e). AnandTech was lucky enough to have this chance, so we recommend that you read their test of the integrated graphic card in Core i5-4950HQ. By the way, it also includes a comparison with Intel HD Graphics 4600 (GT2) that was tested by us (we were able to do that thanks to Core i5-4670K).
But even HD 4600 seems to be an improvement in comparison with HD 4000 from Ivy Bridge. It has twenty execution units and its clock speed is dynamically increased up to 1,200MHz per core during high-load performance intervals. 1GB of memory was reserved for graphics; the memory ran at a clock speed of 1,600MHz and a timing of 8-8-8-24-1T.
Before we look at the Haswell's graphic card from a technological point of view, let us first talk a little about drivers. Intel is obviously targetting less expert users and it won't let you “under the hood” as much as AMD or nVidia.
Haswell Graphics: architecture and performance classes
As we have known for quite a long time now, Intel prepared three distinct performance classes of Haswell's graphic core instead of traditional two (unofficially, they are called GT1, GT2 and GT3). The new GT3 class represents a new performance level that is above the models that Intel had so far; in addition, a special version with integrated eDRAM will be created. However, the architecture of execution units, or shaders, if you want, is not new – it has been transferred from the Ivy Bridge generation. The DirectX 11.1, OpenGL 4.0 and OpenCL 1.2 standards are supported, but Intel has developed its own specific extensions (PixelSync and InstantAccess, look here if you want to know more).
In addition to three (or four) versions of the chip, Intel will confuse things even more by the designation – see the respective slide. The GT1 version will probably be “reserved” for Celerons and Pentiums and it will keep the name of HD Graphics without a numeral. Instead of traditional six execution units, this version will have ten of them, so its performance should be better. GT2 will become HD 4200, 4400 or 4600. This graphic core will be used with both desktop processors and notebook chips of the M, MQ and MX series (in other words, all those that are fitted into a socket), and even Xeons E3 1200 v3; however, we are talking about “professional” P4600 and P4700 versions in this last case. GT2 has twenty execution units (in Ivy Bridge, it had just sixteen).
The most interesting model, GT3 with forty units, will be used only with chips with the BGA package which are soldered directly on to a motherboard. In case of the two-core mobile U series with a TDP of 15W, Intel will call this core Intel HD 5000; for models with higher TDP, it will be labeled Iris 5100. The four-core BGA-based chips (i.e. the mobile H series and desktop R series) will even get eDRAM. This most powerful model will be called Iris Pro 5200.
It is probably the first time that Intel chooses a name for its graphic core that resembles those used by AMD (previously called ATi) and nVidia. Up to now, its names (Extreme Graphics, Graphics Media Accelerator, HD Graphics) have been rather unspectacular. However, it seems that Intel is preparing for a large-scale assault on the whole graphic cards area with Iris, and as this model joins Radeon and GeForce, Intel is no longer a second-rate power, but rather a force to be reckoned with – this is at least what creators hope this new brand will accomplish. But Intel will not have it that easy.
Away with HD, replace it with 4K!
Intel has informed us beforehand about this year's release of screens with a resolution twice as fine as present day standard “Full HD”, or 1920 × 1080 pixels. Therefore, Haswell increases the supported resolution up to so-called “4K”. The maximum graphic resolution will depend on several factors, the main one being an output. Through DisplayPort, Haswell will support a resolution of up to 3840 × 2160 pixels (at a clock speed of 60Hz) thanks to the 1.2 version upgrade, and the same goes for built-in LCD in a notebook (through the eDP interface). HDMI will also support the 4K resolution (up to 4096 × 2304 pixels), but only up to 24Hz.
An analog output will not be available on processors with integrated chipsets (the U and Y series); however, it will be available on conventional processors with separate south bridges (that contain the necessary hardware) and it will be capable of handling 1920 × 1200 pixels at 60Hz. Nevertheless, its activation will limit the maximum resolution on primary eDP (i.e. the notebook's screen) to 2880 × 1800 pixels. Regardless, processors with integrated chipsets will have their resolution limited to 3200 × 2000 pixels both through eDP and DisplayPort.
In general, the graphic card can handle three monitors at once. The Panel Self Refresh function will be important for notebooks – it consists in placing the memory buffer directly into LCD so that screen image can be restored without any additional interaction with the rest of the computer. Therefore, if nothing is going on on the screen, the CPU and the graphic card can turn themselves off. Until now, this hasn't been possible, as the graphic core had to “re-draw” the screen image over and over again (usually like sixty times per second) no matter what actually was on the screen. However, this will likely be fairly rare, at least for some time – to be able to use this feature, a notebook needs a special (more complex and more expensive) LCD.
Haswell introduces a new version of the Intel WiDi technology (version 4.1) which should be able to achieve lower latency; if the target device supports the Panel Self Refresh technology, it should also save energy (if you are transferring an image from a notebook that runs on batteries, wireless streaming is relatively demanding in terms of power input).
The Quick Sync circuit is also there – a specialized block for multimedia tasks. In Haswell, its form has changed quite a lot. An integrated decoder supports a video in the 4K resolution (official materials don't mention one specific number, but it seems that both 3840 × 2160 and 4096 × 2304 pixels will be supported); decoding of the MJPEG, MVC and SVC formats will also be added.
The post-processing options were extended: you can now convert gamut or framerate. Intel also brags about the skin tones “enhancement” and the stabilization of shaking video via the scene global movement compensation. These functions will probably have their own hardware now (Video Quality Engine). Before that, Intel was using execution units for post-processing (the reason once again being to save energy).
The integrated encoder was greatly improved. It now supports new formats – not only traditional MPEG-2, but also more interesting SVC. That is a format based on H.264 which allows for one stream to be decoded in several different resolutions. A video created by this encoder is therefore usable with a wide variety of devices with different levels of performance (a mobile phone gets a normal-quality video while a desktop gets an HD video with high bitrate). However, they have to support SVC – this format isn't very common. But it could be of great use not only in internet streaming, but also when it comes to video conference software.
According to available tests, Quick Sync is already one of the best hardware encoders; Haswell should improve even further on the output video quality. It should be possible to set certain parameters in order to increase image quality (at a cost of speed); three profiles should be available – quick, normal and high quality. All in all, video converting should be a bit faster than with Ivy Bridge.
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