AMD: Limited OpenCL performance for Radeon HD 4000

Robert Hallock 28 Dec, 2009 at 1:01pm ET Article published in Tech

Though Radeon HD 4000 parts became widely popular due to their low prices and high performance, AMD says that the GPUs will have limited performance in OpenCL applications.

“There are known performance issues for ATI Radeon HD 4000-series of cards on OpenCL and there is currently no plan to focus exclusively on improving performance for that family. The ATI Radeon HD 4000-series was not designed for OpenCL, whereas the ATI Radeon HD 5000-series series was. There will be performance improvements on this series because of improvements in the ATI Radeon HD 5000-series, so it will get better, but it is not our focus,” said AMD Senior Compiler Engineer Micah Villmow.

This admission should come as no surprise since the Radeon HD 4000 series dates back to 2006, which predates the finalized OpenCL standard by two years. It’s a testament to the forward-thinking design of the 4000-series that OpenCL is supported at all.

“ATI Radeon HD 4000 just has to be programmed differently than the ATI Radeon HD 5000-series to get performance because of the lack of proper hardware local support. It is possible to get good performance, just not with a direct port from CUDA. […] For example, if you are using local memory, they are all currently emulated in global memory. […] This can cause a fairly large performance hit if the application is memory bound. On the ATI Radeon HD 5000-series series, local memory is mapped to hardware local and thus is many times faster than the ATI Radeon HD 4000-series,” Villmow continued.

In short, the firm admits that the performance will be lower than the GeForce 200 series and the Radeon HD 5000 series, but it is not yet clear how significant this performance impact will be.

Comments

28 Dec 2009 ~ 1:29pm lordbean Unsurprising. The HD4000 series is old tech, and rightly showing its age. Good incentive to move to a newer card.
28 Dec 2009 ~ 1:35pm Garg I welcome the admission. It seems like in most situations like this, companies just decline to support older hardware entirely. Now at least the 4000 series is an option, and people know they need to program around its limitations.
28 Dec 2009 ~ 9:24pm Tim 4000 series is old tech? What ?!?!?! I just bought my 4870 back in January!!! It CAN'T be considered out of date yet, can it?
28 Dec 2009 ~ 9:41pm mas0n

Tim wrote:

4000 series is old tech? What ?!?!?! I just bought my 4870 back in January!!! It CAN'T be considered out of date yet, can it?

the Radeon HD 4000 series dates back to 2006, which predates the finalized OpenCL standard by two years.

In this regard, yes. The 4000 series is old tech.
29 Dec 2009 ~ 2:37am milkmandan Agreed, 4000 series is old tech. :\

@Tim: it is considered old tech, i mean it runs everything you want 'now' fine, but give it another year and it will really really start to show.
this article here is just an example of the HD4000 showing its age.
29 Dec 2009 ~ 4:00pm mirage Even 5000 series cards will be "old tech" until we start seeing applications benefiting from OpenCL.
30 Dec 2009 ~ 7:11pm ardichoke

mirage wrote:

Even 5000 series cards will be "old tech" until we start seeing applications benefiting from OpenCL.

Not true. 5000 series is bleeding edge tech. Opposite of old tech.

Old tech: software has surpassed (or is starting to surpass) the abilities of the hardware.
Current tech: Software is able to utilize, but has not yet surpassed the abilities of the hardware.
Bleeding edge tech: software is not yet able to utilize the hardware fully.

Or at least that's the way I look at it.