RV870 in total control of GDDR5
Even if the memory controller of the RV870 architecture is similar to the one found in RV770 and the Radeon HD 4000 series AMD decided to revise this key component as well. It has made some minor optimizations of the memory controller, but primarily it is the expanded support for GDDR5 that arouse our interest. The memory controller now supports Error Detection Code (EDC), which optimize performance and stability at high memory clock frequencies. Which is very fitting since the Radeon HD 5000 series use memory frequencies up to 5GHz. CRC is even more important in GPGPU where calculation errors and faulty graphics memory could result in some major problems.
Radeon HD 5870 ships with 1GB GDDR5 memory
Last but not least the memory controller has a lot better control of the function of the GDDR5 memory and can change both clock frequencies and voltages in realtime depending on settings and load. Something AMD has used when revising the power consumption of the new chip.
Basically, AMD has made sure the new Radeon HD 5000 series will be better at handling high GDDR5 clock frequencies and we will see speed well above 5000MHz when overclocking, most likely even with factory overclocked models of Radeon HD 5870 that is expected to appear within weeks.
 RV870 memory controller |
It’s time to look at how AMD will counter NVIDIA’s GPGPU technology CUDA.
