A question of StreamWrite latency

Discussion created by hphung on Sep 10, 2009
Latest reply on Sep 22, 2009 by luxert


I find a strange phenomenon when I develop ATI Stream application.

As we my expect, the latency of StreamWrite depends on the level of VGA cards.

However, the strange thing is that, in my experiment, the latency of StreamWrite is "longer" for higher level VGA.

For example, using 1.4 SDK, the latency of writing a grey level HD (1920x1080) image in Radeon 4890 is 5.8ms, however in Radeon 3450, it only takes 4.8ms. (The resuts are the long term average)

Can anyone explain the reason behind this observation? Is that a driver issue or just due to different architectures of different VGAs.