UMA

5/15/99

Unified Memory Architecture (UMA) -- An initiative for low end graphics. The idea is to store graphics information directly in main memory rather than on the graphics card or graphics accelerator card. The advantage of UMA is that it substantially reduces system cost, and chipset complexity. The drawback is that it places a substantial additional load on the system bus since a steady graphics load must be supported rather than just occasional updates.

The economics of UMA look good to equipment designers -- especially for low end consumer and office usage. An additional factor is that LCD displays are expected to become common in future years. LCD displays that are digitally driven may not require periodic updates of static displays. They may require much less memory bandwidth than CRTs when the content is not constantly changing.

The principle problem with UMA would appear to be that when display type or content requires high display bandwidth, display and processing requirements are likely to clash. It is hard to see how strategies useful for enhancing video RAM performance can be implemented in main memory without degrading the random access performance for computing.