Radeon HD 4770s In CrossFire
So how much graphics muscle are you really getting for $220, and how does that compare to the competing single-GPU solutions?
Two Radeon HD 4770s give you 1,280 total shader processors, two 512 MB GDDR5 frame buffers (each on a 128-bit bus), 32 total ROPs and the ability to filter up to 64 textured pixels per clock. Each board in the CrossFire configuration runs a 750 MHz core clock and memory at 800 MHz—effectively 3,600 MT/s.
Why is CrossFire so gosh-darned viable right now? For several generations of chipsets dating back to the 955X Express, Intel platforms have supported the multi-card rendering technology. AMD chipsets dating back to the Radeon Xpress 200 also extend support. So, there’s a huge install base of core logic and motherboards that are compatible.
In contrast, Nvidia has historically limited its SLI technology to Nvidia’s own AMD-/Intel-based chipsets. It was only recently made available on another vendor’s platform via licensing (Intel’s X58). Clearly, Nvidia is realizing that a protectionist policy isn’t the way to go. In fact, we even heard of one motherboard vendor whose budget X58 boards originally didn’t support SLI, were BIOS-hacked to enable it, and then worked-through with Nvidia on a proper implementation—all without having to pay for the license!
How about the oft-mentioned (by Nvidia) concern that, because ATI doesn’t have as close a relationship with game developers—specifically those involved in its TWIMTBP program—that CrossFire is riddled with compatibility issues? There’s actually some validity to such a worry, especially if you enjoy picking up games as soon as they're released. We've seen titles, such as FEAR 2, where CrossFire compatibility is specifically listed as a known issue. Fallout 3 with quad-GPU CrossFire can also be problematic, according to ATI's own Catalyst release notes.
At the same time, none of the games in our test suite gave us trouble. CrossFire isn’t perfect, but after seeing what a pair of 4770s can do slung together, you’ll want to reconsider your reservations.
| Radeon HD 4890 | Radeon HD 4870 | Radeon HD 4770 CrossFire | GeForce GTX 280 | GeForce GTX 260 C216 | |
|---|---|---|---|---|---|
| Manufacturing Process | 55 nm TSMC | 55 nm TSMC | 40 nm TSMC | 65 nm TSMC | 55 / 65 nm TSMC |
| SPs | 800 | 800 | 640 x 2 | 240 | 216 |
| Core Clock | 850 MHz | 750 MHz | 750 MHz | 602 MHz | 576 MHz |
| Shader Clock | 850 MHz | 750 MHz | 750 MHz | 1,296 MHz | 1,242 MHz |
| Memory Clock | 975 MHz GDDR5 | 900 MHz GDDR5 | 800 MHz GDDR5 | 1,107 MHz GDDR3 | 999 MHz GDDR3 |
| Frame Buffer | 1 GB | 1 GB / 512 MB | 512 MB x 2 | 1 GB | 896 MB |
| Memory Bus Width | 256-bit | 256-bit | 128-bit x 2 | 512-bit | 448-bit |
| ROPs | 16 | 16 | 16 x 2 | 32 | 28 |
| Price | ~$250 | ~$190 | ~$220 | ~$310 | ~$180 |
Power And Heat
The Radeon HD 4770 earned praise for its 40 nm technology and resulting cut in power consumption. Indeed, it uses the least power at idle and under load of any other graphics card we tested here.
But what happens when you add a second board in CrossFire? As expected, power consumption jumps significantly. At idle, the two 4770s use more power than any of the single-GPU solutions. Under load, however, the 40 nm RV740 retains its advantage and ducks in under the Radeon HD 4890 and Radeon HD 4870 1 GB cards, using more power than the GeForce GTX 260 Core 216.
If you were looking for more information on the 40 nm process’ effect on GPU temperature, here you go. These were all measured through GPU-z after 10 minutes of idle and then a series of looped 1920x1200 Crysis runs in a window.
You can see that a lone Radeon HD 4770 is the coolest of ATI’s cards at both idle and under full load. Interestingly enough, though, each board required a slightly different fan speed in order to achieve its temperatures. We'll see if these results correspond to overclocking in just a bit.
Been looking to replace my ol' 8800gtx xxx edition for a while and i do have a crossfire board, hmmm
*Darts off to find a 8800gtx Vs 4770 x-fire chart*
I was going to pay AU$225 for a 4850, but for AU$300 I'm now getting 2x 4770's. Awesome
Now I am regretting the 4870 1GB I bought. They really say that as soon as you buy it, it's outdated.
could one xfire a 4770 with a 4850? or better just to xfire 2x 4850?
Cheapest I could find a 4770 in the UK was $123 inc. sales tax. That's not too bad compared to $109 in the US, although you guys may be able to get some form of rebate.
I really like this card. Lots of people are asking me to price up a spec for a comparatively cheap, but still capable GTA IV gaming rig. I can now offer them an AMD Phenom II rig, with either one or two 4770's. Crucially, I don't have to worry about the machine coming back because it's over-heated or they're tweaked the CPU/graphics too hard. That for me is a big bonus. Awesome card(s) with lots of power whether you're Intel or AMD.
Great article Chris.
Bet these turn up as an X2 soon.
I guess you need to update this one once 1GB 4770 cards come out, as the extra frame buffer might even get things nastier for the rest of the competition...
I wonder how NVIDIA will reply to this...
They could always rebadge something like the G92 ... for the fourth time.
I'd still rather have a G80 GTX ... the real thing had a wider memory bus and crunched some serious triangles.
The G92 was a shrink that just saved a few bucks ... at no saving to the customer.
AMD's shrink saves us a few bucks and two of them seem like a killer pair ... comparable to the 9600GT idea I would say (still cheaper though)
/snicker
+1 to 1GB and X2 versions of the card. AMD would be stupid not to! All we need now is the OpenGL physics to go mainstream and we're laughing!
Nice gear. Something for me to look forward to as a CrossFire virgin.
My next rig most certainly gets two of these.
"Below 1280x1024, however, things slow down too much to be considered playable." Above, surely?
£78.53 For a single Sapphire 4770 512Mb inc tax! Maybe I'll finally upgrade my 3870X2 with 2 of these or wait for a 1Gb / X2 version! WIN!
I don't think they have to pull out a X2 card, just up the memory and memory bus. The only problem I can think of is that it will kill the rest of their cards, as I don't believe we'll have to pay more than $50-75+ for this addition alone.
Great performance scaling. Sometimes more than 100%. Weird though.
You can prolly now get 2 for under $200 US Chris ... keep us posted !!
It's not just the FPS that matters...but heat, noise, power consumption...
Not always 2 cards are better than one, unless we talking about Crysis..
http://www.ebuyer.com/product/164568
83 GBP over there, a HD 4770. Thats quite good. and the performance, very good!
I´m kinda regretting buying my 4870 now too
. Though all is not yet lost!
In a couple of months I´ll get either another 4870, 4770 or a better card, depending on what seems like the best choice.
It seems everyone has fallen in love with the 4770 crossfire but when you think about it, your already limiting yourself. For those with 4870 once you put them in crossfire they will also outperform these configs.
Each user has a different budget. The 4890 is not at danger as it can overclock nicely as well as be arranged in crossfire blowing away the competition. Remember directX11 cards are also coming in September.