Review: GPU-accelerated video-encoding. Who is better, AMD or NVIDIA? - Graphics - HEXUS.net

How we test

GPGPU testing setup
Motherboard	Foxconn Bloodrage X58
Processor	Intel Core i7 965 Extreme Edition. 3.2GHz
Memory	6GB (3 x 2GB) Corsair DOMINATOR PC-12800
Memory timings and speed	9-9-9-24-1T @ 1,333MHz
Graphic cards	HIS Radeon HD 5870 1,024MB and BFG GeForce GTX 295 1,792MB
Power supply	Corsair HX1000W
Hard drive	Seagate Barracuda 7200.12, 1TB
Optical drive	Sony SATA DVD-RW

The application can’t utilise more than four threads per video encode, so four copies of the same input file were queued up, enabling the Intel Core i7 965 CPU cores to be fully utilised.

In order to ensure the encoding takes place simultaneously, the maximum concurrent file conversions were set to four.

On the ATI testbed one can also enable hardware decoding, however this seemed to cap the performance, thus making it slower than CPU-only encoding. Appreciating this, we left it disabled.

The input file used was of the following specification: Video – 2 minutes 28 seconds, 1,920x1,080 MPEG-2 HD, 35Mbps bit-rate, 25fps frame-rate, progressive-scan. Audio - stereo, MPEG-1 Layer II, 48KHz, 384Kbps.

The output file used the default parameters for the YouTube profile as follows: Video – 2 minutes 28 seconds, 1,280x720, H.264, 1.93Mbps bit-rate, 29fps frame-rate, progressive-scan. Audio – stereo, AAC-LC, 44KHz, 220Kbps.

The screenshot, below, highlights which settings were selected in the application.

Click to enlarge

Despite CyberLink reporting to the contrary on its website, the level of customisation on offer is extremely limited. For example, there is no adjustment of the audio output parameters other than the format used. In addition you can only choose a very limited selection of output resolutions, not helped by the lack of bit-rate or frame-rate adjustment. As such the output frame-rate on both NVIDIA and AMD systems is incorrect. It spits out 29fps whereas it should have been 25fps.