AMD ATI Radeon 3850 & 3870 review

Next to shrinking that die-size ATI did make another clever move, the move back to the 256-bit memory bus (still using the 512-bit ring-bus). It's much cheaper to work with memory and less expensive to integrate. So combining these factors can make the overall products less expensive. RV670 also makes the move towards PCI-Express 2.0 compatibility which doubles the bus (PCIe) data rate towards 16GB/s. Not that we need it at this time though... although with CrossfireX... it might make a difference.

	ATI Radeon HD 2600 ATI Radeon HD 2900 ATI Radeon HD 3850 ATI Radeon HD 3870 # of transitors 390 million 700 million 666 million 666 million Stream Processing Units 120 320 320 320 Clock speed 600-800 MHz 742 MHz 670 MHz 775+ MHz Memory Clock 800-2000 MHz (effective) 1.6 GHz (effective) 1.66 GHz (effective) 2.25 GHz (effective) Math processing rate (Multiply Add) 144-192 GigaFLOPS 475 GigaFLOPS 428 GigaFLOPS 497+ GigaFLOPS Texture Units 8 16 16 16 Render back-ends 4 16 16 16 Memory 256Mb DDR2, GDDR3 GDDR4 512MB GDDR3 512MB GDDR3 512MB GDDR3/4 Memory interface 128-bit 512-bit 256-bit 256-bit Fabrication process 65nm 80nm 55nm 55nm Power Consumption (peak) ~45W ~215W ~90W ~105W

ATI CrossfireX
I sincerely hope that ATI will support Crossfire in their games better then they did in the past. This quite honestly is a big Achilles heel for the Crossfire gaming experience. None the less, today they are introducing CrossFireX. IF AMD will get this working right then it's the bomb as it allows you (with selected mainboards) to combine one, two, three or even four graphics cards together in Crossfire mode. That's a lot of future redundancy.

We tried to push for some CrossFire results on an Intel 975 Platform, yet to find out that the mainboard had just died. Sorry, no Crossfire results today. We do expect a Phenom system later this week with a new RD790FX mainboard allowing this new form of multi-GPU gaming. We will do a follow-up article on this. So just remember this, you can game with four graphics adapters simultaneously. Ehm, you could connect up-to eight monitors and so on. The upcoming Catalyst driver release will fully support this feature, and hey .. it'll even allow overclocking on the multi-GPU based platform. Good stuff, and something we'll look deeper into very soon.

HD Decoding with UVD
One of the features lacking in the 2900 XT was the new UVD video decoder engine. UVD provides hardware acceleration of H.264 and VC-1 high definition video formats used by Blu-ray and HD DVD. The video processor allows the GPU to apply hardware acceleration and video processing functions while keeping power consumption & CPU utilization low. When the HD 2900 XT was released it took the press by surprise that the low-cost HD 2400 and 2600 where able to post-processes and accelerate HD streams like VC1 and H.264 fine while the 400 USD counterpart missed that engine and thus that translated into much higher CPU utilization.

That no longer the case, we ran a HD-HQV test and noted sheer decoding perfection on both the HD 3850 and 3870. Low CPU utilization whilst scoring a maximum of 100 out of a 100 points. One other improvement has been made as well you can now upscale your 1920x1080 streams fine towards for example a 2560x1600 sized monitor (no more black borders).

HDMI & HDCP compatibility
Obviously the entire HD 3000 series of cards will offer HDMI connectivity with the help of a DVI adapter or native with a HDMI connector integrated into the card, all cards fully support the DRM cancer called HDCP. Unlike most current HDMI implementations on PCIe graphics cards, this HDMI solution also incorporates audio functionality into the GPU. 

Your series 3000 card can directly output audio over HDMI – removing the need of a separate sound card over your HDMI connector.  Where it'll output that sound in 16-bit PCM Stereo sound or AC3 5.1 compressed multi-channel audiostreams as Dolby Digital and DTS. A feature, especially for those who use their PC as a HTPC and are connecting HDMI towards a HDMI receiver.

So with the Series 2000/3000 you'll receive a DVI-to HDMI adapter which, and make no mistake here, will carry sound over HDMI. That's unlike current DVI-HDMI adapters and cables which do not carry sound. Fantastic if you are watching a Blu-ray movie, simply connect HDMI towards your HDTV for PCM sound, or connect it through a TrueHD/Dolby HD receiver and get that sound lovin' going on through that receiver of yours. All with one simple cable.

Here we can see that DVI to HDMI dongle that is supported with the HD 300 series Radeon graphics cards.

I have to note that some board partners are now slowly making to move to integrate a HDMI connector on the graphics card. TUL (PowerColor) for example submitted a card today that has HDMI integrated.

DirectX 10.1
New in both the Radeon HD 3850 & 3870 is support for the DirectX 10.1 API, introducing a new layer of extensions. DirectX 10.1 is expected to launch with the Windows Vista Service Pack 1 and is backwards compatible with the existing DirectX 10 layer. Make no mistake, DX10.1 fully supports DX10 hardware. And DX10.0 class cards will still play DX10.1 games just fine.

It's basically an update to DX10 that extends the hardware functionality slightly. All the hardware is still supported, all the games still run, all the features are still there, it's just simply extended the feature set and the lifetime of the API. The release mainly sets a few more image quality standards for graphics vendors, while giving developers more control over image quality. Features scheduled for DirectX 10.1 include:

• Mandatory 32-bit floating point filtering
• Mandatory 4x anti-aliasing
• Shader model 4.1

DirectX 10.1 will get updated with the availability of Windows Vista SP1. Until this point in time, Microsoft managed to avoid the subject of the final release of SP1. However, speculations point to either the end of 2007 or to early 2008 as possible release dates.

Right, we're going to have a brief look and walk-through at what we'll test today. We have the AMD HD 3870 reference sample, HIS HD 3850 & 3870 samples, and TUL (Powercolor) also submitted their HD 3850 to be reviewed in this article.

In alphabetical order we'll start off with the AMD reference model.