HYPERMEMORY AND TURBOCACHE

HyperMemory and TurboCache - boy they sure do sound fast, don't they? Leave it to ATI and nVidia to use marketing speak to turn something that's really actually bad for the consumer into something positive.

Since graphics hardware has made the transition from AGP to PCI Express, it can now access system memory at much faster speeds, and as a result, graphics parts can dynamically share system memory. ATI's implementation is called HyperMemory; nVidia's is called TurboCache. By implementing these technologies, they can create cheaper parts that require less dedicated video memory. There are differences in the two implementations, however.

nVidia's TurboCache has features dedicated to its operation built into the graphics chips themselves. As a result, their interface with system memory is usually quite fast. Unfortunately, this also results in a greater number of parts outright relying on this technology.

ATI's HyperMemory, on the other hand, is done entirely in software, and is enabled on virtually all of their hardware. While conceivably this is a bonus and should at least marginally improve performance on any system with ATI hardware, the flipside is that most often the latency is too poor for it to be of any real benefit to any but the lowest grade of parts.

The major problem with these technologies - and nVidia is particularly guilty of this - is that they basically allow manufacturers and resellers to "lie" about the amount of dedicated video memory the part has. nVidia parts in the Low End and Mainstream categories are going to be guilty of this, and it may or may not matter to you as these parts are still fairly solid if unexceptional performers. The only way you can really know how much video memory these parts have, though, is if they say something like "x Dedicated / x TurboCache or Shared."

ATI's parts, apart from the X300 and X1300 are much less guilty of this, and I've found that ATI usually ships more than an adequate amount of video memory with their X1000 series parts. The flipside is that their HyperMemory technology is, as I stated before, pretty unremarkable.