Most modern video cards can deliver enough pixels to drive a mid-sized monitor (think widescreen 19- to 22-inch displays with a native resolution of 1680×1050) – at least until you sit down to play a high-end game. At that point, a PC equipped with a low-end video card turns into an expensive slideshow projector.
Upgrading your system’s video card is easy enough, but a high-end card that’s capable of delivering just about any game at 60 frames per second at a given resolution—our minimum performance requirement—can cost $400 or more. And while it wasn’t long ago that we’d never recommend a video card in the sub-$100 price range for serious gaming, PowerColor’s Radeon HD 4670, which is street-priced at just $90, surprised us by coming close. This card has all the features you’d want for other applications too, including the capability to offload Blu-ray video-decoding chores from the host CPU.
Features and Design
The Radeon HD 4670 at the heart of PowerColor’s card is manufactured by AMD, and it packs a lot of power into a very small container: 514 million transistors jammed into a package measuring just 145mm2. The GPU (graphics processing unit) boasts 320 stream processing units—the electronic micro engines that execute the programming code to produce graphics on your display—which is the same number you’ll find in AMD’s previous-generation high-end GPU, the Radeon HD 2900 XT.
The Radeon HD 4670 hasn’t exhibited much of a propensity for overclocking (operating the processor at a higher frequency than AMD’s reference design), and PowerColor toes the line by running this one at a stock clock rate of 750MHz, despite the presence of an oversized heatsink and fan. AMD’s 4000-series GPUs tend to run hot, but PowerColor’s cooling apparatus kept temperatures manageable without producing a lot of undesirable noise.
PowerColor pairs the GPU with a large frame buffer: A full gigabyte of GDDR3 memory. What the heck is GDDR3? The GDDR acronym stands for Graphics Double Data Rate, and it’s a type of memory specifically developed for use with graphics processors, as opposed to CPUs (AMD’s Phenom or Intel’s Core i7, for instance). Double data rate means that information is transferred on both the rising and falling edge of the clock cycle, so that the memory’s effective data rate is twice that of its clock rate.
In this example, PowerColor runs the memory at a clock rate of 873MHz, but because it uses GDDR3 memory, the card’s effective memory clock rate is 1,746MHz. The benefits of a large frame buffer materialize when you’re playing games that use Microsoft’s DirectX 10 technology and when you’re using high levels of anti-aliasing to eliminate the jagged edges in curved lines. But this advantage is somewhat offset by the fact that the Radeon HD 4670 has a memory interface that’s just 128 bits wide (higher-end GPUs have 256-bit or even wider interfaces). PowerColor also sells a version of this card with a 512MB frame buffer that’s about $15 cheaper, and that’s probably a better a value for most people.
But if you’re upgrading a PC that uses integrated graphics, you’ll see not only a significant boost in overall performance, but you’ll also free up system memory too. And unlike many GPUs that deliver this level of performance, the Radeon HD 4670 does not require more electrical power than a PCI Express slot can deliver, so you don’t need to worry about supplementing it with juice from your PC’s main power supply.
If your PC’s motherboard supports CrossFireX—AMD’s multi-GPU technology—you can link any two Radeon HD 4670 cards together to achieve even more performance (frame rates won’t necessarily double, due to overhead, but you will see a significant boost). CrossFireX isn’t limited to AMD CPUs, either; motherboards based on most modern Intel core-logic chipsets (the P35, P45, P965, 975X, X48, 5400, and X58) are a compatible with CrossFireX.
The card has two dual-link DVI outputs on its mounting bracket, which renders it capable of driving a 32-inch display at its native resolution of 2560×1600 (although you’d never want to try playing a game that way). There’s also an analog S-video output that can be connected to a television set, and PowerColor provides a dongle that converts that analog output to composite video. The Radeon HD 4670 has a sound chip integrated into its die that can route high-definition audio to the DVI port, so that when you plug in the provided DVI-to-HDMI dongle, you can pipe both multi-channel audio and video to your display or A/V receiver using a single cable. The card is HDCP compliant, which means it’s capable of playing Hollywood movies on Blu-ray discs.
Benchmark Performance and Conclusion
As we mentioned earlier, you’ll want to play games at frame rates of a least 60 frames per second to achieve the most realism. PowerColor’s Radeon HD 4670 came very close to that with at least one of three games we used for benchmarking (we used Valve’s Steam game delivery system to play Infinity Ward’s Call of Duty 4: Modern Warfare, Ubisoft’s Far Cry 2, and Crytek’s Crysis at the native resolution of a 22-inch ViewSonic VX2240w LCD monitor – 1680×1050 pixels).
The PowerColor card managed to deliver Call of Duty 4: Modern Warfare at 54.4 frames per second—and with 4x anti-aliasing enabled, no less! (We used Fraps to measure frame rate while playing an in-game cut scene generated with the game’s custom engine.)
Call of Duty 4 is a blast to play, but it’s not exactly at the bleeding edge when it comes to gaming graphics. When we fired up the more demanding Far Cry 2 and used the game’s built-in benchmarking tool, we found we had to turn off anti-aliasing altogether. Even then, with the game’s overall quality setting on “high” and using DirectX 10 mode, the Radeon HD 4670 managed to squeeze out only 40.5 frames per second.
The card had an even tougher time with Crysis, the most graphically intense—and arguably the best-looking—game on the market today. Even with the game’s quality setting dialed back to “medium” and with AA turned off, we could coax just 24.4 frames per second out of this card. If you intend to play either of those games on a Radeon HD 4670, you’ll need to turn the resolution way down.
So the Radeon HD 4670 isn’t a great gaming GPU, but it does deliver a compelling price/performance ratio. Pairing it with a 1GB frame buffer, as PowerColor does here, provides a theoretical advantage in terms of anti-aliasing, but that becomes a moot point if you find yourself turning AA off in order to increase frame rate. If your primary video card application is watching Blu-ray movies, you’d be better served by the 512MB version of this card.
- Dual-link DVI
- Doesn’t require supplemental power
- 1GB frame buffer
- CrossFireX compatible
- Single card isn’t fast enough for gaming at high resolution
- Dongle required for HDMI output
- 128-bit memory interface