Why You Can Trust CNET Sapphire Radeon HD 4850 X2 (PCI-e 2.0 review: Sapphire Radeon HD 4850 X2 (PCI-e 2.0
Sapphire Radeon HD 4850 X2 (PCI-e 2.0
AMD bestowed its ATI Radeon HD 4850 X2 graphics chips exclusively onboard partner Sapphire to bring to retail. It started at $399 when it launched back in November, but prices have come down as low as $299 for the 2GB version reviewed here. At that price especially, we find the Sapphire Radeon HD 4850 X2 the best midrange 3D hardware currently available. In addition to demonstrating very fast performance, the Sapphire Radeon HD 4850 X2 is also unique in supporting up to four displays on one PC. We recommend this card to any gamer interested in a reasonably priced investment in greater 3D power. We would also suggest it to anyone looking for a straightforward means to quadruple your screen real estate.
Sapphire Radeon HD 4850 X2 (PCI-e 2.0
The Good
The Bad
The Bottom Line
As with the Radeon HD 4870 X2, the 4850 X2 is a dual-chip 3D card. Powered by two Radeon HD 4850 GPUs, the X2 version is effectively a self-contained Crossfire setup. You need to connect this card directly to your PC power supply via one six-pin and one eight-pin PCI Express power input. And as a double-wide card, it also takes up a fair amount of space inside your PC. That said, no other card in this price range offers the same performance or overall capability.
| Sapphire Radeon HD 4850 X2 | EVGA Geforce GTX 260 Core 216 Superclocked | |
| Price | $299 | $259 |
| Manufacturing process | 55nm | 55nm |
| Core clock | 625MHz (2) | 576MHz |
| Stream processors | 800 (2) | 216 |
| Stream processor clock | NA | 1242 MHz |
| Memory | 2GB | 898MB |
| Memory speed | 933MHz DDR3 | 2.0GHz DDR3 |
Nvidia has two graphics cards that compete with the Radeon HD 4850 X2. On the lower end, the updated 216 core GeForce GTX 260 comes in around $260 in an overclocked model from EVGA. You can also find the Geforce GTX 280 for about $315. Price fluctuations and rebates make it hard to pin down the exact price of any 3D card, and while the GTX 260 has consistently been the most affordable of the three tested here, the Radeon HD 4850 X2 has fluctuated from $399 at launch, to anywhere from $299 to $340 or so today, with changes occurring daily on NewEgg.com. Amazon's price has held steady at $299, this week at least, and hopefully that will remain consistent. Regardless, we expect the HD 4850 X2 and the GTX 280 will continue to compete on price for the foreseeable future.
(Longer bars indicate better performance)
 | 1,400x960 | | 1,680x1,050 | | 1,920x1,080 |
(Longer bars indicate better performance)
| 1,440x900 | | 1,680x1,050 | | 1,920x1,200 |
(Longer bars indicate better performance)
| 1,440 x 900 | | 1,680 x 1,050 | | 1,920 x 1,200 |
Thanks to the Radeon HD 4850 X2's strong performance, this part of the discussion is easy. It's faster on every game we tested, and at every resolution. The Crysis scores aren't that far apart, and all three cards struggle with our admittedly aggressive image quality settings, even at 1,440x900. Dial down the antialiasing or overall image quality and you should expect an improvement by 10 frames or so across the board.
If Crysis is perhaps too demanding, Far Cry 2 is more or less the sweet spot for 3D testing right now, as it's a bit more forgiving than Crysis, but still looks great by current standards. None of these cards had trouble with our Far Cry 2 test, but the Radeon HD 4850 X2 was the fastest overall, and the only one to break the 60 frames per second barrier at 1,920x1,200, the native resolution of most current 24-inch wide-screen LCDs. If you own a 30-inch display, you may want more headroom, but for 24 inches or fewer the Radeon HD 4850 X2 has you covered for most current titles, and with a little bit of headroom to spare for games down the road.
The only caveat we'll add to the performance discussion is that because this is a dual-chip card, it relies on the scalability of 3D games to put both chips to good use. If a game or the card's driver software falters, you may see limited performance. Two recent cases in point: Far Cry 2 had an issue with cards using ATI's CrossFire multichip technology (since resolved), and as of this writing, the PC version of Grand Theft Auto IV won't recognize Nvidia chips in SLI mode. Single-chip cards, like the two from Nvidia in this price range, don't have that issue. We think the speed benefits of the Radeon HD 4850 X2 are worth the risks, but it's also worth noting that the possibility of a scaling issue is indeed real, particularly in the early days of a game's release.
(Shorter bars indicate better performance)
| Load | | Idle |
As has been the trend in other recent 3D card reviews, ATI has fallen behind Nvidia on power efficiency. It might not surprise you that a faster, dual-chip card needs more juice than comparably priced single-chip cards, but it's still worth spelling out the difference. Interestingly, the Radeon card is comparatively more efficient at load than it is at idle, but in either case, the extra performance has a real-world cost in terms of power consumption.
If this card doesn't quite deliver on power efficiency, it can actually have a direct impact on your productivity, at least if you use screen real estate as your scale. AMD has been unique in equipping certain dual-chip cards with four DVI outputs, and it's one of the features we love about the Radeon HD 4850 X2. We successfully connected four LCDs from different vendors and of different screen sizes. The card identified all of them successfully, and let us operate in either clone mode, with the same image mapped on all four screens, or in extended mode, which extends one desktop screen across every display.
Perhaps counterintuitively, you need to turn off Crossfire mode to output to four monitors. ATI's driver software makes that easy, though, as it also gives you relatively robust controls for arranging the displays in whatever order you want, and also adjusting each display's settings. Adding four displays doesn't necessarily mean you can all of a sudden play a game at 7,680x1,200, as most games will only scale to preset resolutions, and/or require specific code to support multiple monitors. You can, however, put a game on one screen and a Web-based map and a walkthrough on the others. And of course the idea of showing a spreadsheet, e-mail, and multiple Web pages at the same time will make many office functionaries drool. With each port dual-link DVI enabled, in theory you should be able to connect four 30-inch LCDs to one Radeon HD 4850 X2. We weren't able to test four 30-inchers, but we were pleased with the experience of connecting the 24-inch, 22-inch, and pair of 19-inch displays we had on hand.
Finally, as a member of AMD's Radeon HD 4000-series, this card has all of the DirectX 10.1, stream processing, and Havok Physics acceleration inherent to all the chips in that family. When we actually see those features have a widespread software impact, we'll be sure to write about them.
Test bed configuration
Windows Vista Ultimate SP1 64-bit; 3.2GHz Intel Core i7 965; Intel X58 chipset; 4GB 1,066MHz DDR3 SDRAM; 150GB 10,000rpm Western Digital Raptor hard drive