ATI’s HyperMemory

ATI’s HyperMemory technology is used in the company’s RADEON X300 SE graphics cards, based on the RV370 core. ATI’s RV370 core is fully DirectX 9 compliant, supporting Shader Model 2.0, just like the RADEON X600 and RADEON 9700 PRO. The RV370 chip within RADEON X300 SE features four pixel pipelines, a 325MHz core clock, and ships with a 300MHz memory (600MHz effective) memory clock speed.

Since the X300 SE is limited to a 64-bit memory interface, the X300 SE boasts up to 4.8GB/sec of local memory bandwidth, which is then combined with 8GB/sec of system memory bandwidth, providing the RV370 core with 12.8GB/sec of total bandwidth, just keep in mind that there is a latency penalty that will kick in when the card accesses system memory.

As we stated earlier, HyperMemory uses the high speed bi-directional data transfer capabilities of PCI Express to store and access graphics data in system memory. HyperMemory works by using intelligent memory allocation algorithms to optimize the use of local system memory as graphics memory.

These algorithms decide where the data should be placed, the most important data is stored locally on the graphics card; data that can’t fit locally is stored as GART memory, which is non-paged system memory that is assigned to the graphics card. Once GART is full, data is stored in pageable system memory. HyperMemory can access local graphics memory and system memory in parallel, which helps to optimize performance.


The ATI RADEON X300 SE ships in two flavors, one with 32MB onboard that supports up to 128MB of memory, and another with 128MB onboard that supports 256MB of total memory. Both HyperMemory cards use a 64-bit memory interface and ship at the same 325MHz core/300MHz memory clock speeds, the only difference is the amount of memory onboard, with the 32MB RADEON X300 SE being the most popular. Prices range from $45-$55, depending on the manufacturer.

RADEON X300 SE Configurations
Card	Core Clock Speed (MHz)	Memory Clock Speed (MHz)	Onboard Memory Size	Width of Memory Interface	Peak Onboard Memory Bandwidth
RADEON X300 SE HyperMemory 128MB	325	300	32	64	4.8
RADEON X300 SE HyperMemory 256MB	325	300	128	64	4.8

For our testing today, we’ll be using the ATI-built RADEON X300 SE 128MB card pictured above.