Compute Performance

With the 11.3 Catalyst drivers AMD started including their OpenCL runtime with the drivers, a long-awaited development that we’re hoping spurs additional OpenCL development. With that change AMD’s marketing posture has once again shifted towards advertising their GPGPU capabilities, though the 6450 isn’t a great platform for this. With 160 SPs its twice as capable as the 5450, but this is still around 1/10 the theoretical capabilities of their high-end cards, and there the difference between the GPU and the CPU often isn’t the same 10x difference.

In short the 6450 isn’t very fast for GPGPU computing tasks, and indeed Cyberlink’s MediaEspresso won’t even allow hardware encode acceleration on the 6450. This is probably the only notable weakness for the 6450 as an HTPC platform—the decoding is great, but it has no hope of catching up to Intel’s Quick Sync for encoding.

Our first compute benchmark comes from Civilization V, which uses DirectCompute to decompress textures on the fly. Civ V includes a sub-benchmark that exclusively tests the speed of their texture decompression algorithm by repeatedly decompressing the textures required for one of the game’s leader scenes. Note that this is a DX11 benchmark.

With only 160 SPs the 6450 achieves very limited performance here.

Our second compute benchmark of the day is SmallLuxGPU, the GPU ray tracing branch of the open source LuxRender renderer. While it’s still in beta, SmallLuxGPU recently hit a milestone by implementing a complete ray tracing engine in OpenCL, allowing them to fully offload the process to the GPU. It’s this ray tracing engine we’re testing. Note that as Intel doesn’t currently offer an OpenCL driver for their HD Graphics iGPUs, we’re only looking at dGPUs here.

We’ve cut off all the scores above 10K rays/second just to make the 6450 fit, which should give you an idea of the relative performance. The 5770 at $50 more easily gets 4x the performance.

StarCraft II Power, Temperature, and Noise
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  • lukechip - Thursday, April 7, 2011 - link

    In the April 2011 Video Card MSRP list, you've omitted the Radeon HD 6950 2GB. Given that this was the first 6950, and in my mind, the 'real' 6950, why is it not listed ?
  • Ryan Smith - Thursday, April 7, 2011 - link

    The MSRP list isn't mean to be a definitive list of every card at every price point; but still, that was a rather silly omission. I've since added it.
  • ImSpartacus - Thursday, April 7, 2011 - link

    Also missed the GTX 590, but I understand that the purpose of the chart was to show the 6450's position, not to be completely and ultimately definitive.
  • Ryan Smith - Thursday, April 7, 2011 - link

    No, that would be because I'm an idiot.

    The chart was taken from the GTX 550 Ti article, which predated the 590 (which is why it's not there).
  • GeorgeH - Thursday, April 7, 2011 - link

    This might be a great HTPC card for an existing box, but unless AMD has seriously screwed up I can't see this card being terribly attractive for much of anything once Llano ships.
  • ImSpartacus - Thursday, April 7, 2011 - link

    I would've liked to see some discussion on that topic. Llano will probably be pitiful on the CPU end, but if they can cram a strong GPU into the product, these $50 GPUs will eventually become extinct.
  • starfalcon - Thursday, April 7, 2011 - link

    I suppose with Llano and Ivy Bridge, discrete graphics for HTPC use will essentially be extinct.
    For gaming I wonder if they will be willing to release any low end graphics that can be beaten by IGPs, if not, then I wonder what the lowest end cards they will release will be.
  • vol7ron - Thursday, April 7, 2011 - link

    I agree, unless they will be used in other ways. I'm not sure what max resolution IGPs can support. Also, I'm sure if you use the HTPC as more of a PC than HT, you will probably need the additional parallel processing (or dedicated GPU).

    All-in-all these cards remind me of dedicated cards from the 90s :)
  • starfalcon - Friday, April 8, 2011 - link

    I know IGPs can do 2560x1600.
    With Sandy Bridge I think it only can do it with display port but besides that 1920x1200 with HDMI/DVI. Shouldn't be a problem.
    What will you need the additional parallel processing for?
    Or dedicated GPU?
    Sandy Bridge supports quick sync and Llano should have lots of processing capabilities, Ivy Bridge should have more and more stuff also.
  • vol7ron - Sunday, April 10, 2011 - link

    Say you're playing a game, want to put it on pause and watch some TV, or have multiple display setups and want to watch TV while playing a game. Add a DVR capture card and you'll be need more CPU and GPU processing.

    I'm just not sure how great the performance would be. Especially assuming you wanted to attach this to a 46"+ display. It might be "capable", but we all know that word is very misleading and quality is hard define when you don't see it with your own eyes.

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