Processor and Components Continued
Moving along to the memory we were supplied. We have Corsair's 2GB Dual Channel memory kit supporting DDR2-800 speeds with low latencies and a standard 1.8v operating voltage. The kit gives us a total of 2GB of system memory. With the onboard graphics sucking between 32MB and 512MB for its frame buffer on a sliding scale, the more system memory you can put in there, the better.
Now we get along to our discrete graphics card. Now, I hear a few of you asking "Why would we have a discrete graphics card if we have a motherboard with onboard graphics?" - This is simple; 780G is AMD's first chipset to support Hybrid Crossfire. A little refresher course is in order I think.
Crossfire is AMD/ATIs version of NVIDIA SLI for combining two or more graphics cards together in order to produce a better 3D processing engine which allows the sharing of workload, similar to how Dual Core CPUs work. Now we have the first AMD chipset that allows you to do this, providing you have a certain ATI graphics card to combine the power of the Integrated GPU with the power of the discrete GPU. What does this mean?
Simply put, when the system is in 2D mode, very little is required to run the windows desktop; this can easily be handled by the integrated GPU. When 3D applications start to come into play, it is necessary to get more power, since Integrated GPUs are limited because of the amount of system memory they can use along with the limited memory bandwidth they have at hand. Since the CPU needs to share this bandwidth, you need a bit of a kick in the pants, and Hybrid Crossfire is what allows us to do this.
As a standard setup, when the system is in Windows just idling, the integrated graphics handles the desktop rendering, shutting the external graphics card off. This reduces the amount of power required. When the 3D applications start, the discrete graphics card is enabled through a command along the SMBus. When this happens, the two graphics cards will work together to render the 3D scenes.
The graphics card we were supplied was a passively cooled ATI Radeon HD 3450 from HIS. The large heatsink on the graphics card will be extremely important as we plan to use the system as silently as possible. We plan to run with only one fan on the CPU at as low RPMs as possible; so, the GPU needs to be able to run silently. Thanks to the passive cooler, it can. Furthermore, it'll run with a better power profile as opposed to a higher-end offering. This system is going for speed, stealth and power friendly goodness.
The hard disk we decided to use for our test system was actually a last choice; we were simply going to use our standard 500GB Seagate hard disk we normally use, however we were supplied with a Western Digital Green Power 1TB drive for another article we are going to be doing very shortly. This drive runs with lower power, and has better power management features when the system is at idle, such as a low power spin down allowing the drive to conserve as much power as possible, as well as running quieter than most hard disks on the market.