ATI Radeon HD 4200:
The AMD ATI (Mobility) Radeon HD 4200 is an onboard (shared Memory) graphics chip (on the RS880M chipset). It is based on the HD 3400 graphics core and features the UVD 2 video engine to decode HD videos (Avivo HD - can decode two HD streams simultaneously).
Compared to the old HD 3200, the 4200 now supports DirectX 10.1 and features the UVD2 video decoder.
Hybrid CrossfireX is a new feature of the chipset, that allowes to use the onboard HD 4200 graphics core in conjunction with a dedicated graphics card (of the Mobilty Radeon HD 3400 series) in Crossfire combination to increase the performance (similar to GeForceBoost / HybridSLI of Nvidia). Every frame is rendered by a different graphics core with this technique.
The UVD 2 video engine is able to decode HD videos (MPEG-2, H.264, and VC-1) in all stages and allows the fluent playback of HD videos (e.g. Blu-ray) with a relative low CPU utilization (called Avivo HD). The HD 3200 was the first onboard graphics card that allows the fluent playback of Blu-ray videos. The UVD 2 on the HD 4200 supports the decoding of two video stream and therefore got a full Blu-Ray support.
The graphics core of the HD 4200 stems from the Mobility Radeon HD 3400 and is therefore DirectX 10.1 capable. Because of the missing graphics memory, the performance of the card is a bit lower than of the HD 3400. Theroretically, dedicated memory chips can be directly added to the chip, making it a dedicated graphics card. Because of pricing it is unclear if any manufacturer will add memory to the chip.
Still older games like Doom 3 or Quake 4 should be barly playable. Compared to older onboad graphic chips (e.g., GMA X3100), the HD 4200 is much faster. Even the Centrino 2 graphics core (GMA 4500M HD) is noticeable slower than the HD 4200. Compared to the HD 3200 the performance should be similar
Using Windows XP, the HD 3200 seems to have problems with current and older drivers, as there is no 2D accelleration. This leads to very slow interactions with windows and scrolling (especially with Firefox as reported in various discussion boards). More information on the topic can be found at Planet 3D Now (de) or the AMD forum. It is still unclear if the HD 4200 also suffers from this problem.
ATI Mobility Radeon HD 4570:
The ATI Mobilty Radeon HD 4570 from AMD is a DirectX 10.1 lower-middle-class notebook graphics adapter. Technically it is a faster clocked Mobility Radeon 4530/4330.
AMD specifies a slow 64 Bit memory bus, but some GPU-Z variants state a 128 Bit bus (should be an error).
The gaming performance of the ATI Mobility Radeon HD4570 should be very similar to the desktop HD 4550 which features similar specifications. Benchmarks of the desktop card showed, that the most DirectX9 titles can be played fluently in high details and 1024x768 (like Call of Duty 4, F.E.A.R., UT3, World in Conflict). Demanding games like crysis only run in low-medium detail settings in decent frame rates.
The Mobility HD 4570 is based on the RV710 chip and features 80 stream processors (16 5-dimensional shader cores). These cores do the graphic work of the shader- and pixel pipelines of older GPUs. The stream processors are also called ALUs and are grouped in five-way VLIW units. Each of the five instructions of a VLIW bundle has to be independent from the others and therefore the performance depends on the optimization of the driver.
A speciality of the Radeon HD 4570 is the possibility to use ordinary DDR2 and DDR3 graphic memory (as a cheaper alternative to GDDR3). However, cards that use that kind of memory will be slower than others equipped with GDDR RAM.
The Mobility Radeon HD 4570 includes the Avivo HD called video technology including an onboard soundchip for 7.1 sound output over HDMI or DisplayPort and the 2nd generation UVD (Unified Video Decoder). This UVD 2 supports full bitstream decoding of H.264/MPEG-4 AVC and VC-1 streams. In addition to this, it also supports dual video stream decoding and Picture-in Picture mode which makes the UVD full BD-Live compliant. Simplified, the Avivo HD technology handles all video tasks and enables the GPU to decode HD videos.
AMD published a current consumtion of about 12-15 Watt for the HD 4570. Still it is unclear if this value represents the chip alone or the whole mxm board including the memory (which would include about 5 Watt).
Compared to the desktop ATI Radeon HD 4550, the mobile 4570 features a higher core clock (680 versus 600) and therefore performs a bit better than the desktop 4650 (if the notebook manufacturer uses GDDR3 memory).
As 4200 series is a older verison and work less I suggest 4570.
Thnaks:)