Tuesday, June 14, 2011

Saving Power with GPGPU and AMD Fusion

I'm currently pondering the benefits of GPGPU on AMD's Fusion processors from a performance and power consumption perspective. To scratch this itch, I have starting to look into how well the OpenCL applications in the Phoronix Benchmark Suite run on my AMD E-350 netbook. I'm looking at the performance from both a throughput as well as from a power consumption perspective.

So far from a few quick tests, the performance looks like about 60%-100% better on the integrated GPU core than running the applications on the CPUs. Power-wise, the system's power consumption (as measured by the battery drain through ACPI) seems to be about 2 watts better when running on the GPU versus the CPU (overall system power ranges from ~12w-19w.

I decided to start looking into this for several reasons:

1. AMD's Fusion products have relatively better GPUs than they do CPUs. As a result, GPGPU could potentially have a large benefit on Fusion systems.
2. The mobile Fusion GPUs are designed for relatively low-power systems; as a result, the GPU's power consumption should be relatively modest as compared to a lot of discrete GPU applications. The low power of the GPU opens up the potential to utilize GPGPU to save power.
3. GPGPU performance is frequently heavily limited by memory bandwidth; as a result, it would be interesting to see if a GPGPU application has an advantage over a CPU-based application when they have access to exactly the same memory.

Before I spend too much time studying this question on my netbook, I'm wondering what other people think.

There, I Fixed It

It looks like I might be the first person to get Bluetooth working on the HP dm1z netbook/ultraportable: