We are Rendering 16 live Streams at our client machine through one of our applications and the resolution of the video streams are as 4CIF/MPEG4/25FPS/4000Kbits.

The configuration of the client machine is below.

HP Desktop Machine:

Microsoft Windows XP Intel (R) Core2 Duo CPU E8400 @ 3.00 GHz 2.99 GHz, 1.94 GB of RAM Intel (R) Q45/Q43 Series Express Chipset (Inbuild)

The CPU usage of the machine peaks 99% for 16 streams.

After some discussion, we had decided to install external graphics card to reduce the CPU usage.

So that, we have tried following graphics cards.

1. NVIDIA Quadro NVS 440 - 128 MB
2. Radeon HD 4350 - 512 MB GDDR2
3. Redeon HD 4350 - 1GB DDR2
4. ASUS EAH 4350 Silent 1GB DDR2

But the performance wise there has been no difference - even a drop in performance.

So, what is the purpose of these external graphics cards?

Really it will reduce the CPU usage? What parameters have to check, if we want to reduce the CPU usage?