What is important in choosing a Video Graphics Card?
posted this on December 22, 2012 11:32 AM
This is a good question. SmartSDR for Windows is a WPF application that automatically uses utilizes your video graphics card's hardware acceleration capabilities. This does not mean that you need to go out and purchase a high-end gaming graphics adapter to use with SmartSDR, but there are a few guidelines that will assist you in making a graphics card purchase if you need to do so.
Rule of Thumb: You do not need to over spend for a top end 3-D gaming graphics video card to run SmartSDR.
The minimum DirectX support for your graphics card and graphics card driver is version 9 or greater. Version 10 or greater will provide the best possible performance.
Graphics Processing Unit (GPU) Type
Most graphics cards today use either the AMD (previously ATI), Intel or NVIDIA GPUs. All work equally well, but AMD drivers seem to have lower DPC latency than NVIDIA. If you are using a motherboard with and AMD processor and AMD chipsets, an AMD graphics card will pair up nicely with it. If the PC motherboard uses NVIDIA chipsets, then an NVIDIA graphics card might have a slight advantage over an AMD and Intel GPUs.
Video Card Bus Type
Older PCs will have Advanced Graphics Port (AGP) type bus slots for installing graphics adapters. Newer PCs have x16 Peripheral Component Interface Express (PCI-E or PCIe) as the standard way to connect the graphics card to the motherboard. PCI-Express offers roughly twice the data transfer rate of 8x AGP, so if you have a choice, use the PCI-E slots. Verify what kind of bus slots your PC has before purchasing a video card.
GPU Processor Clock Speed
The greater the clock speed, such as 2 GHz vs. 3 GHz does not automatically mean that the later graphics card will have twice the performance. Sometimes 3 GHz clock speeds are slower than 2 GHz if they are based on an inferior GPU architecture. We recommend that you check out hardware testing sites like Tom's Hardware Guide and read the reviews on different video cards.
Graphics Card Memory
The biggest misconception out there is that more graphics RAM will increase video performance. But, for the most part, this is untrue. There is a minimum amount of graphics RAM recommended for WPF applications like SmartSDR-Win, but more RAM does not necessarily translate into better operational performance. While the bandwidth of the graphics RAM might have a direct effect on video performance, the quantity of RAM doesn't have a direct impact on how fast a graphics card performs.
The bandwidth of graphics card RAM is affected by two main factors: the clock rate and interface width. Clock rate is measured in MHz, just like a CPU. The width of an interface is measured in bits, such as 128-bits wide. Without going into too much detail, you should know that 200 MHz memory should provide twice the bandwidth of 100 MHz memory, assuming everything else is equal. Similarly, a 128-bit memory bus should provide twice the bandwidth of a 64-bit bus.
For running SmartSDR-Win 512 MB of 128-bit graphics RAM is the recommended minimum amount for optimal performance. This is not a requirement as SmartSDR-Win will function with video card having less video RAM, but it will result in higher CPU utilization.
3-D vs. 2-D Graphics Capabilities
A lot of high-end gaming video cards are very expensive because they have exceptional 3-D rendering capabilities. SmartSDR is primarily a 2-D application, but the ability to support 3-D spectrum displays in the future is a possibility. It is recommended that you do not need or will need the exceptional 3-D graphics capabilities of these high-end gaming video adapter, so there is no compelling reason to purchase a very expensive graphics adapter.
PassMark software is used to benchmark PC hardware and give it a relative performance ranking. There are PassMark rankings for video cards which can be used to evaluate video different cards. You can access the PassMark Video card benchmark database at: http://www.videocardbenchmark.net/
A video card with a PassMark ranking of 600 or greater is recommended for use with SmartSDR for Windows.