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Updated: AMD 785G: The Venerable 780G, Evolved

Radeon HD 4200 Enhancements

For years now, we've wished that someone would come out with an IGP capable of handling today's games at reasonable detail settings and at resolutions of at least 1280x1024, which is the lowest resolution at which I'd be happy playing.

The Radeon HD 4200 built into AMD's 785G chipset is, unfortunately, not the realization of this dream.

Don't get me wrong. The 785G is a great IGP, but it's pretty much exactly as great as the 780G before it, as the performance-oriented specifications have remained essentially identical: 40 stream processors, four texture units, and four ROPs. The 785G even runs at the same clock speed as the 780G, 500 MHz.

So what's different abut the 785G graphics processor? DirectX 10.1 support is the obvious answer. And, well, not much more as far as hardware specifications go:

AMD 785G AMD 780G AMD 790GX
Integrated Core RV620RV610RV610
DirectX/OpenGL 10.1/2.110.0/2.110.0/2.0
Shaders/TU/ROP40/4/440/4/440/4/4
Graphics Clock 500 MHz500 MHz700 MHz

As suggested by the name 785G, this is an incremental upgrade. The DirectX 10.1 enhancements will not offer any immediate performance benefits for the end-user. DirectX 10.1 features can be enabled, but these won't likely speed up the frame rates, as we will demonstrate in our game benchmarks.

While the chipset's 785G designation reflects minor improvements, the name of the Radeon HD 4200’s GPU is quite a bit more provocative. Given its name, one might assume that the Radeon HD 4200 (785G) is superior to the Radeon HD 3300 (790GX), which is not the case when it comes to gaming. The 790GX is clocked at 700 MHz, while the 785G is clocked at 500 MHz. And with everything else being pretty much equal, the 790GX is, of course, notably faster.

The bottom line is that the AMD 790GX and Nvidia GeForce 9400 remain the fastest gaming IGPs out there. As for the good news, most 780G or 785G chipsets should be able to overclock to 790GX specifications or a little higher without cooling modifications, so the end-user can experience passable 1024x768 gaming performance with a little tweaking. This is fine for the casual gamer, but discrete graphics remains the only solution for more demanding settings.

Things might get interesting in the next generation of IGPs if AMD integrates something similar to the Radeon 4350 with its 80 shader processors into a chipset, but I suspect we might not see that for a while yet, as it'll likely require a manufacturing shrink. And when that happens, the day's games will be more demanding and the cycle of pain will continue.

Note that some 785G-based boards will have an advantage over early 780G platforms, because they seem more likely to sport SidePort memory. The cache, consisting of 128 MB of DDR3, serves as dedicated video RAM for the IGP, boosting performance slightly. While some 780G motherboards do offer SidePort memory, it's much more common on the 790GX chipset.

  • macer1
    the real question is how would this perform if mated to an Atom processor in an nettop.
    Reply
  • mcnuggetofdeath
    "refined architecture" ? To my knowledge, and please correct me if im wrong, all that was changed between the original phenom and the phenom 2 was the addition of more L3 cache allowing it to do more simultaneously and a die shrink allowing for higher clocks. That does not a refined architecture make. When AMD added an on die memory controller to their processors years ago they had made a huge advancement in architecture. Im sad to see them fall away from the performance crown. Here's hoping their new Bull Dozer architecture brings something genuinely intriguing to the table.
    Reply
  • mcnuggetofdeath
    ^^^ and support for DDR3. Although thats a change to the board, not the CPU.
    Reply
  • anamaniac
    Very interesting.
    A integrated GPU that can game. =D

    Makes my lil Pentium D with a 4670 seem puny...
    3.3GB/s memory bandwidth (single channel DDR2 533... though 2 sticks, it runs in single channel... damn prebuilts) also seems sad on my rig...

    macer1the real question is how would this perform if mated to an Atom processor in an nettop.
    Good question. A dual core Atom with a 4200 integrated would be nice.
    We all know Intel makes shitty mothebroards and AMD makes kickass motherboards anyways.
    Reply
  • SpadeM
    mcnuggetofdeath^^^ and support for DDR3. Although thats a change to the board, not the CPU.
    Not correct, the P2 has a built in memory controller so the switch to ddr3 affected that controller
    Reply
  • apache_lives
    anamaniacVery interesting.A integrated GPU that can game. =DMakes my lil Pentium D with a 4670 seem puny...3.3GB/s memory bandwidth (single channel DDR2 533... though 2 sticks, it runs in single channel... damn prebuilts) also seems sad on my rig...Good question. A dual core Atom with a 4200 integrated would be nice.We all know Intel makes shitty mothebroards and AMD makes kickass motherboards anyways.

    Native ram for a pentium d is PC4200 which has a max of 4.2gb/s per channel etc and the FSB has the max of 6.4gb/s

    The Intel atom would most likely underpower any video card out there, and Intel does actually make a good reliable business platform where video performance is not required etc
    Reply
  • I'm sorry, is this an Intel benchmark site? All other reviews put SYSTEM power consumption for Athlon II 250 well below Intel E7200.
    Reply
  • aproldcuk
    This article raised a lot of questions for me. What about Hybrid Crossfire for example? What kind of cards can be used together with this new IGP? Is the discrete graphics card on standby if no performance is required? If no then how much extra outlet wattage is expected? And how much extra if actively in use? I'm interested in using the 785G solution in the 24/7 HTPC setup with the possibility to do occasional gaming as well. My current setup with 690G chipset and Athlon 64 X2 BE-2350 CPU draws around 50 watts most of the time and up to 90 watts under heavy load. Is it too much to expect similar levels from 785G and Phenom II X3 705e combo for example?
    Reply
  • wh3resmycar
    when can we see the mobile version of this? this is most certainly a welcome update compared to the 780g-hd3200 chipset. and beats any nvidia igp hands down. id love to see this on an $700-$800 laptop. good thing im still holding back on buying a new notebook.
    Reply
  • Pei-chen
    Good timimg, I was wondering if 785G is better than 790GX or not yesterday. Thanks.
    Reply