After Nvidia introduced its entry-level GeForce 9 Series graphics-processing-unit (GPU) lineup, we expected a response from AMD, and that company wasted no time in giving us one.
After all, AMD's ATI division has been on a serious roll lately, and its high-end Radeon HD 4800 line has been taking Nvidia to town. The Radeon HD 4870 X2 is the fastest single-card solution on the market, and the Radeon HD 4850 and 4870 are the price/performance leaders of their class. Now AMD is moving to seize the low-end segment by launching the Radeon HD 4600 series.
While Nvidia seems content to introduce redesigned GeForce 8 Series cards as re-branded GeForce 9 models, AMD has built every member of its Radeon HD 4000 series on the new R700 core architecture. This has brought impressive performance gains in each market segment -- the single-GPU Radeon HD 4870 challenges the previous-generation, dual-GPU HD 3870 X2 -- along with a consistent feature set.
Extending this to the entry level are the new Radeon HD 4650 and 4670, which offer the new architecture for about $69 and $79, respectively. Their specifications are a little strange at first glance: The new cards' 320 stream processors are the same as the Radeon HD 3870's, while their 32 texture units are double that card's count.
Clock speeds are also high, with the HD 4650 set at 600MHz and the HD 4670 at 750MHz. On paper, the Radeon HD 4650 and 4670 look like enhanced versions of the HD 3850 and 3870, the last of which was AMD's last-generation mainstream performance model.
Of course, you won't really be buying a Radeon HD 3870 equivalent for $79; AMD has ensured some separation by implementing that old favorite of the economy segment, a 128-bit memory interface instead of the 256- or 512-bit memory link of a mainstream or high-end card. The restriction cuts the same-clock memory bandwidth of a Radeon HD 4650/4670 to half that of an HD 3850 or 3870. The Radeon HD 4850 carries a modest 512MB of DDR2 at 1GHz as well, though the HD 4670 is available with 512MB or 1GB of GDDR3 clocked at up to 2GHz.
The new Radeons are also low-power units, checking in at 48 watts for the HD 4650 and 59 watts for the HD 4670, with no external power connectors required for either card. This will allow their use with entry-level and small-form-factor systems, lowering both power usage and heat production compared to a comparable previous-generation graphics card. Performance per watt is also something AMD is heavily promoting, which is a smart move given the current logjam in the sub-$100 graphics segment.
Moving from one bottom line (price) to the other (performance), the ATI Radeon HD 4650 and 4670 are stunning achievements. Even with the smaller 128-bit memory interface, the $69 and $79 cards compete well against last-generation mainstream performance cards. The lower memory bandwidth does hamper the cards a bit at higher resolutions, but the GPU makes up for it. Frankly, this level of performance is unheard-of in a card with an under-$80 price tag.
As mentioned, the Radeon HD 4670 easily outperforms the HD 3850 and comes very close to matching the HD 3870, a model that was AMD's single-GPU flagship not long ago. The new cards also handle antialiasing and anisotropic filtering duties with ease, as the R700 core has been enhanced for these features. The 4650/4670 also use less power than the 3850/3870 cards, and manage to put the lockdown on the Nvidia entry-level competition as well.
Multi-GPU technology is another area in which AMD has taken a leadership role, and the company's current CrossFireX implementation is supported throughout the new 4600 series. This is not only important from a scalability point of view, but also helps AMD's marketing effort by promising a quick-fix graphics upgrade if required: The overall cost benefit is intriguing, as you can spend $79 now and then double up for another $79 (or less) later on.
And, thanks to Intel adopting the CrossFire architecture, odds are better that you own a supported motherboard. By cultivating an uneasy relationship with Intel, and incorporating CrossFire from top to bottom -- even in the 780G and 790GX integrated-graphics chipsets-- AMD has made CrossFire almost a household name. Except for those using Nvidia's own nForce chipsets, virtually all high-end desktop motherboards support AMD's multi-GPU technology, and many mainstream platforms do as well. Intel is a powerhouse in the performance desktop market, and AMD is happy to come along for the ride.
By contrast, Nvidia views its SLI technology as a major selling point of its nForce motherboard chipsets and, aside from the Intel Skulltrail bridge-chip experiment, has been loath to allow it outside these confines. That works fine for the company's platform department, but maintaining a proprietary hold on SLI has definitely hurt Nvidia's graphics-card sales. It's sort of a Catch-22: Nvidia would gain more of the graphics pie if SLI was opened up to Intel platforms, but then the nForce line would be extremely vulnerable.
The release of the Radeon HD 4600 is an impressive one, but with only one problem -- the previous-generation ATI and Nvidia performance cards are no longer priced at $150 to $200. As faster GPU architectures emerge and new card lines are added, last year's models trickle down the price list, usually settling in the sub-$100 range. Radeon HD 3850 512MB cards can now be found for around $90, while the more powerful HD 3870 512MB costs not much more than $100.
It's the same story with the GeForce family, as last-generation powerhouses like the GeForce 8800 GT and 9600 GT 512MB boards hover right around the $100 mark, while lower-clocked GS and GSO variants set up shop in the $80-to-$90 range. This creates additional competition, even at $69 to $79.
Even so, the new AMD Radeon HD 4650 and 4670 cards should do well simply based on their combination of mainstream performance and low power usage. One thing is for sure -- buyers can get a lot more for a C-note than ever before.