Now we will try to sum up the test data and make our final verdict about the capabilities of an ATI CrossFireX tandem consisting of two Radeon HD 4670 graphics cards. Can you improve your computer’s graphics performance by purchasing a second 4670 card if you’ve already got one? Will this upgrade be worth the trouble? Let’s discuss each resolution starting from 1280x1024.
The CrossFireX tandem boasts superb scalability: the average performance gain over the single Radeon HD 4670 is 85%. The frame rate even occasionally grows up by 100% and more, like in Devil May Cry 4, Prince of Persia and Mass Effect – without any degradation in image quality! The only exception is Red Alert 3 where the performance gain is only 15%.
Comparing it with more advanced single-chip graphics cards, the Radeon HD 4670 CrossFireX enjoys an average advantage of 7.7% over the Radeon HD 4850 and 14.5% over the GeForce GTX 9800+. It loses but few tests to them and by no more than 9%, excepting Red Alert 3 where the CrossFireX tandem has serious problems with scalability. On the other hand, it is not as much faster than the mentioned single cards as to justify your replacing them with two Radeon HD 4670 cards, especially as the new recommended price of the Radeon HD 4850 is a mere $129. However, purchasing a second Radeon HD 4670 for your graphics subsystem is a good and inexpensive way of increasing your computer’s graphics performance if your mainboard supports CrossFireX technology.
As opposed to the Radeon HD 4830 CrossFireX tandem described in our earlier report, the Radeon HD 4670 CrossFireX cannot beat the faster single-chip cards such as GeForce GTX 260 Core 216 and Radeon HD 4870 1GB. It is slower by 11% and 16%, respectively. The occasional victories (like the 12% lead over the GeForce GTX 260 Core 216 in X3: Terran Conflict) should not be viewed seriously: the Radeon HD 4670 CrossFireX is no match to the mentioned single-chip products from ATI and Nvidia.
The CrossFireX platform behaves in the same way at 1680x1050, offering an average 82.5% performance growth over the single card, but its advantage over the Radeon HD 4850 has shrunk from 7.7% to 4.6% whereas its gap from the Radeon HD 4870 1GB and GeForce 9800 GTX+ has grown wider to 20% and 14.3%, respectively.
So, we can say it once again: purchasing two Radeon HD 4670 cards for building a CrossFireX configuration does not make sense. It is better to buy a single Radeon HD 4850 instead. Such a configuration is only reasonable when you buy a second Radeon HD 4670 in addition to the one you already have.
Oddly enough, it is at the resolution of 1920x1200 that the Radeon HD 4670 CrossFireX enjoys the highest success. It beats the Radeon HD 4850 and GeForce 9800 GTX+ by 8% and 18.5%, respectively. However, it is still 21% and 14% behind the Radeon HD 4870 1GB and GeForce GTX 260 Core 216, respectively. The CrossFireX tandem cannot close that gap.
The efficiency of CrossFireX technology is as high as at the lower resolutions: the two cards enjoy an average 85% advantage over a single Radeon HD 4670. And like in the previous cases, the overall positive picture is somewhat marred by poor scalability in Red Alert 3.
Comparing the Radeon HD 4830 CrossFireX and Radeon HD 4670 CrossFireX tandems, we should confess that the latter has vaguer perspectives. Although its performance is higher than that of Radeon HD 4850 and GeForce 9800 GTX+/GeForce GTS 250 cards, the difference is not as big as to make the multi-GPU tandem more appealing than a single, more expensive, card that occupies only one PCI Express x16 slot. Moreover, this difference can be rather easily eliminated by means of overclocking. In terms of power consumption the tandem is more economical than a Radeon HD 4850 (94 against 110 watts) but less economical than a GeForce GTX 9800+/GeForce GTS 250 that uses a 55nm G92 core and consumes only 80W.
So again, such a subsystem can only be interesting for people who already have one Radeon HD 4670 and a CrossFireX-compliant mainboard. Considering that the Radeon HD 4670 is an entry-level solution, there is a low chance of the user having such a mainboard. Entry-level systems are usually based on mainboards with only one PCI Express x16 slot. Moreover, the owner of a Radeon HD 4670 CrossFireX will face all the problems associated with modern homogeneous multi-GPU solutions, the most important of which is the dependence on driver optimizations as is indicated by Red Alert 3.
We could not spot any problems with the image quality or stability of the multi-GPU solution except for higher control lags in Far Cry 2. We even performed an image quality check in suspicious cases but could not see any difference. Thus, ATI has done a good job on its driver and the situation has improved greatly since our Crisis Management CrossFireX report.