HD 4870 X2
Hello everybody and welcome to this R700 -- Radeon HD 4870 X2 preview.
We felt we first needed to come upwith a small explanation. Typically when new graphics cards arereleased, previewed or whatever, Guru3D is among the first websites topublish an article on it.
So last week, on Monday, a couple ofwebsites posted a preview while Guru3D did not have our card yet... ourneck hair grew back inwards. Especially considering we had been incontact with AMD regarding this very topic, the X2 cards.
What happened? -- Somewhere within AMDthe decision was made to arrange a preview, with worldwide roughly10-15 boards available for the previews. Within that same line ofreasoning / decision making, these preview boards would begeographically distributed. Meaning, USA, UK, France, Germany,Scandinavia ... but unfortunately the tiny little Netherlands was notincluded, and yes, that's exactly where our office is.
So despite the fact Guru3D writes inEnglish, we were not included for the preview just for the sole fact weare stationed in the Netherlands. It was seriously the biggest cockupI've seen in years. My contacts at AMD however got aware of myfrustration on preview day, last Monday. Guru3D & AMD got in aconference call on Tuesday, and by Thursday we had the preview board aswell.
So on behalf of Guru3D, our apologiesfor the delay, but finally today we'll actually look into a productthat's been a big success since it's release .. yet now doubled up. I'mof course talking about the mighty new Radeon HD 4800 series of cards,the X2. It was already known for a long time that AMD would release aproduct under codename R700. We just didn't know for sure if thatproduct was a single "GPU" based product, or a multi-"GPU" basedproduct.
We now have the answer, in very shortwording, you take a large PCB (printed circuit board), slap two 4870processors and a bridge-chip on there and call it a Radeon 4870 X2.It's surely not the most elegant method of getting a graphics card inthe high-end segment, it is however as this preview will show you, avery effective one.
Before we dive into the preview, weneed to mention that there is one restriction we got from AMD. We canuse any benchmark we want, yet are limited to a small number (fourgames) considering this is a preview. A second note that we must makeis that this is an early beta engineering test-sample, the power savingfeatures are disabled on these boards meaning that IDLE wattage andeven peak wattage will be off by a good number.
Other than that we have a green lightto tell you what we want. Good good .. as it should be an interestingread, let's have a peek first and then slide onto the next page please.
Radeon HD 4870 X2 preview
By:Hilbert Hagedoorn |Edited by John A. Johnsen | Published: July 21, 2008
Select Page to Load1 - Two way introduction2 - First base with R7003 - Second base with R7004 - Installation, GPU temps, power cosumption & noise levels5 - Photos - The Card (1)6 - Photos - The Card (2)7 - Hard- and software used8 - Game Performance: Mass Effect9 - Game performance: Race Driver GRID10 - Game performance: Call of Duty 411 - Game Performance: S.t.a.l.k.e.r. 12 - GPU Performance: 3DMark Vantage 13 - Overclocking & Tweaking14 - The Conclusion | | |
RV770 + RV770 = R700Alright then grab some coffee andlet's get started. Roughly half way through August AMD will release the4800 series X2 products officially. What you see today is nothingfinal. Board-partners are free in their choices, you'll see X2 basedcards with 4850 configurations, 4870 configurations, gDDR3, gDDR5, 1GB, 2GB maybe even 4 GB memory. So that is why I want to mark thisarticle very clearly and specifically as a preview. We'll show someearly rough numbers based on this two-GPU configuration based product.But to understand the Radeon 48x0 X2 graphics card, you must learn alittle more about the GPUs that are empowering the product; which youalready know under the name Radeon HD 4850/4870, yet was developedunder codename RV770.
Going first base with RV770
By launching the RV770 chip, AMDeffective doubled up performance over the last-gen product especiallyfor you at a very acceptable price level. Quite an achievement. Butlet's talk a little about the GPU and the differences between the twomodels that where released (4850/4870), the RV770 based chipset. AMDput nearly a billion transistors into that GPU, which is now built upona 55-nm production.
The chip literally is 16 mm wide andhigh. Which for AMD still is quite large, for a 55nm product. Thenumber of transistors for a midrange product like this is extreme andtypically it's best to directly relate that to the number of shaderprocessors to get a better understanding. But first let's look at somenice examples of Die sizes of current architectures.
One of the two RV770 cores utilized on the R700 product.
The stream/compute/shader processors(can we please just name them all shader processors?) definitely had agood number of changes; if you are into this geek talk, you'll spot 10SIMD clusters each carrying 80 32-bit Shader processors (thisaccumulates to 800 ). If I remember correctly, one SIMD unit can handledouble precision.
Much like we recently noticed inNVIDIA's GTX 200 architecture, the 80 scalar stream processors per unitper SIMD unit have 16KB of local data cache/buffer that is shared amongthe shader processors. Next to the hefty shader processor increase youprobably already noticed the massive amount of texture units. In thelast generation product we noticed 16 units, the 4800 series has 40units.
When you do some quick maths, that's2.5x the number of shader processors over the last-gen product, and2.5x the number of texture units. That's ... a pretty grand changefolks. Since the GPU has 800 shader processors it can produce the rawpower of 1000 to 1200 GFlops in simple precision. It's a bit lame andinaccurate to do but ... divide the number of ATI's scalar shaderprocessors with the number 5 and you'll roughly equal the performanceto NVIDIA's stream processor, you could (in an abstract way) say thatthe 4800 series have 160 Shader units, if that helps you compare ittowards NVIDIA's scaling. Again there's nothing scientific or objectiveabout that explanation.
The number of transistors for aproduct priced like this is quite excessive and typically it's best todirectly relate that to the number of shader processors to get a betterunderstanding. Now please understand that ATI used different shaderprocessors opposed to NVIDIA, so do not compare the two in that manner;but the new Radeon 4850/4870 have 800 shader cores. Effectively thisproduct can poop out 1000/1200 GigaFLOPs of performance. Depending onhow that is measured of course.
An 4870 X2 (R700) has two 4870 cores (RV770) embedded onto the PCB.
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Boththe 4850 and 4870 products utilize the same chip, make no mistake. Whatyou'll notice is that the 4850 will run at a 625 clock frequency andcomes with 512MB GDDR3 memory (framebuffer) clocked at 1986 MHz. Thesetwo factors are pretty much the biggest difference compared to the bigbrother 4870. Power requirements aren't bad either. You can expect a110 Watt peak watt power consumption per GPU in this configuration. That second configuration is obviouslythat sweet Radeon HD 4870. We see exactly the same GPU mounted on thisboard, yet there are some distinct differences to be found. Theperformance of this product is tweaked and maximized. You will noticethat AMD's board partners will have higher clock frequencies on thisproduct boosting out some more performance. Yet more importantly, thisis the product you guys hear so many rumors about .. the product withGDDR5 memory. GDDR5 is a first for sure.
There are some distinct advantages tobe found for GDDR5 memory. It's has much higher frequency based memoryversus tight timings. In the end this gives the Radeon HD 4870 aperformance boost as GDDR5 memory will leverage overall peak bandwidthto a theoretical (roughly) 3.6 Gbps. And that's just crazy fast (GDDR3on 4850 = 2.0 Gbps).
This is the biggest difference betweenthe two (4850/4870) models. Next to the memory, and I already mentionedthis, you can expect higher clock frequency for the core/shader domain,750 MHz will be the default clock frequency and memory wise ... thefrequency sees 3600 MHz.
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Hover with your mouse over this photo to magnify.
Well, just like NVIDIA'sSLI, Crossfire is a situation where you add a second, third or evenfouth similar generation graphics card (or in today's case GPU) to theone you already have in your PC and effectively try to double, triple,quadruple your raw rendering / gaming performance.
The idea isnot new at all though .. if you are familiar with the hardwaredevelopments over the past years you'll remember that 3dfx had a veryfamiliar concept with the Voodoo 2 graphics cards series. There aremultiple ways to manage two cards rendering one frame, think ofSupertiling, it's a popular form of rendering. Alternate frameRendering, each card will render a frame (even/uneven) or Split Framerendering, simply one GPU renders the upper or the lower part of theframe. So you see there are many methods where two or more GPUs can beutilized to bring you a gain in performance.
The R700 as tested today is based on a4870 configuration. You'll spot several models on the actual launchbased on multiple configurations.
Yet the engineering sample that wereceived is based on the 4870 as it has a core frequency of 750 MHz andthe product has it's gDDR5 memory clocked at 900 MHz which quadruplesitself to an effective frequency of 3600 MHz. Doubling up, also meansdoubling up the memory amount, which is now set at 2 GB on this card.See, each GPU will clone that memory. Example, each texture is sittingin both the framebuffers as the GPUs can not share that buffer --cloning.
Let's compile a chart and look at the differenced:
| | ATI Radeon
HD 4850 | ATI Radeon
HD 4870 | ATI Radeon
HD 3850 | Radeon
4870 X2 (R700) | # of transistors | 965 million | 965 million | 666 million | 965 million x2 | Stream Processing Units | 800 | 800 | 320 | 800x2 | Clock speed | 625 MHz | 750 MHz | 670 MHz | 750 MHz | Memory Clock | 2000 MHz GDDR3 (effective) | 3600 MHz GDDR5 (effective) | 1.66 GHz GDDR3 (effective) | 3600 MHz GDDR5 (effective) | Math processing rate (Multiply Add) | 1000 GigaFLOPS | 1200 GigaFLOPS | 428 GigaFLOPS | 2400 GigaFLOPS | Texture Units | 40 | 40 | 16 | 40x2 | Render back-ends | 16 | 16 | 16 | 16x2 | Memory | 512MB GDDR3 | 512MB GDDR5 | 512MB GDDR3 | 1024 GDDR5 x2 | Memory interface | 256-bit | 256-bit | 256-bit | 256-bit x2 | Fabrication process | 55nm | 55nm | 55nm | 55nm | Power Consumption (peak) | ~110W | ~160W | ~90W | ~300W |
And that R700 product we'll look at asAMD want to reveal a bit of what they are working on. Anyway, let'shave a look at the product and talk some more.
Frontlines: Fuel of WarThis is a game that's got a couple ofbig ambitions. The first is to provide a large-scale multiplayerexperience along the lines of Battlefield: Modern Combat. That means inaddition to running around on foot, you can jump in and control avariety of vehicles on the battlefield. However, it also wants to addwhat Battlefield sorely lacks, which is a compelling single-playerexperience. Perhaps the most impressive level is a completely war-torncityscape that has gutted skyscrapers everywhere. Even more startlingis that you can actually get into some of these towering husks, whichgives you an incredibly high perch. While that might seem a bit unfair,keep in mind that there are many ways for other players to get at you,such as the remote-controlled air drones that can fly up and shred youwith guns or rockets.
Frontlines: Fuel of War is a great title we recently added to our benchmark suite.
That's good performance, in-gameeverything possible image quality wise is maxed out. Very goodperformance across the board. Here we see that the 4870 X2is definitely on the lead.
3DMark Vantage (DirectX 10)3DMark Vantage focuses onthe two areas most critical to gaming performance: the CPU and the GPU.With the emergence of multi-package and multi-core configurations onboth the CPU and GPU side, the performance scale of these areas haswidened, and the visual and game-play effects made possible by theseconfigurations are accordingly wide-ranging. This makes covering theentire spectrum of 3D gaming a difficult task. 3DMark Vantage solvesthis problem in three ways:
1. Isolate GPU and CPU performance benchmarking into separate tests,
2. Cover several visual and game-play effects and techniques in four different tests, and
3. Introduce visual quality presets to scale the graphics test load up through the highest-end hardware.
To this end, 3DMark Vantagehas two GPU tests, each with a different emphasis on various visualtechniques, and two CPU tests, which cover the two most common CPU-sidetasks: Physics Simulation and AI. It also has four visual qualitypresets (Entry, Performance, High, and Extreme) available in theAdvanced and Professional versions, which increase the graphics loadsuccessively for even more visual quality. Each preset will produce aseparate, official 3DMark Score, tagged with the preset in question.
The graphics tests will havefour quality presets available: Entry, Performance, High and Extreme.Each preset specifies a certain setting for the rendering optionslisted in section 5.6. The graphics load increases significantly fromthe lowest to the highest preset. The Performance preset is targetedfor mid-range hardware with 256 MB of graphics memory. The Entry presetis targeted for integrated and low-end hardware with 128 MB of graphicsmemory. The higher presets require 512MB of graphics memory, and aretargeted for high-end and multi-GPU systems.
3DMark Vantage is obviously fresh fromthe shelves. We show two scored, first the Vantage GPU score (notoverall score) and in the lower segment, the 3DMark06 score. The newpress driver did some magic for 06 by the way. Not sure what to make ofit. But my general recommendation is simple, focus at the 3DMarkVantage GPU score results for an excellent rated and accurate score.
Gaming: S.T.A.L.K.E.R. - Shadow of Chernobyl Shortly after another disaster inChernobyl, the authorities surround the area with the Russianequivalent of the U.S. National Guard, and they begin to hear weirdscreams and rumblings coming from within. After a while though, most ofthem are returned to earlier posts. Curiosity gets the better of somepeople, so they sneak into the 30-kilometer area to do some goodold-fashioned investigating. These people are called Stalkers, and theyreport back to the authorities with their findings.
The 3D engine shines in a few keyareas, all crucial in shaping the game's atmosphere. It's got a hugedraw distance, which leads to the palpable feeling that this is a bigworld. Lighting and shadowing are its other big strengths. For thisbenchmark we have the in-game settings at maximum (AA/AF enabled),Dynamic lighting was enabled.
Image Quality setting:
- In-game Software Anti Aliasing enabled
- 16x anisotropic filtering
- Dynamic lighting enabled
Stalker we set at maximum quality settings, we enable everything possible, alsodynamic lighting. S.T.A.L.K.E.R. does not support hardwareanti-aliasing, yet uses a software applied method which is enabled aswell. We again see the X2 take of real hard.
Gaming: F.E.A.R. As many of you will be aware, F.E.A.R(or First Encounter Assault & Recon in short) involves a rathermysterious looking girl in a red dress, a man with an unappetizingtaste for human flesh and some rather flashy action set pieces aka TheMatrix. All of this is brought together by one of the best game enginesaround.
F.E.A.R. makes its cinematicpretensions clear from the start. As soon as the credits roll, and themusic starts, you are treated to the full works. The camera pans acrossscores of troops locked 'n' loaded and ready to hunt you down, allseemingly linked to 'Paxton Fettel', a strange kind of guy withextraordinary psychic power capable of controlling battalions ofsoldiers and a habit of feeding off any poor unfortunate innocents -presumably to aid his powers of concentration. It doesn’t end there,after a short briefing at F.E.A.R. HQ you are sent off to hunt downFettel equipped with reflexes that are 'off the chart'. These reflexesare put to excellent use, with a slow motion effects like that of MaxPayne, or the before mentioned Matrix. But here, it is oooohhhh so muchmore satisfying thanks to the outstanding environmental effects. Sparksfly everywhere, as chunks of masonry are blasted from the walls andblood splatters from your latest victim. The physics are just great,with boxes sent flying, shelves tipped over, and objects hurtlingtowards your head. And the explosions, well, the explosions just haveto be seen, and what's so great about this is you can witness it in allits glory in slow motion.
Let me confirm to you that based onthis, F.E.A.R. will have you shaking on the edge of your seat, if notfalling off it. The tension is brought to just the right level with keymoments that will make your heart leap. Play the demo and you will seewhat I mean. The key to this, is the girl. Without revealing anythingsignificant, lets just say that she could take on the whole of Mars forcreepiness.
Image Quality setting:
- 4x Anti Aliasing
- 16x anisotropic filtering
- Soft Shadows Disabled
F.E.A.R. has a built intest which we used to measure performance, you should try it yourself,it's really fun to look and compare with our results. Yet F.E.A.R.after all this time still is a tough title for the graphics cards;especially when you configure it to maximum image quality. This game isheavily pixel shaded and shows some dark and creepy effects. Again 4xAA and 16xAFwhere applied here. All settings to high, no soft shadows. 2560x1600 @the setting shows an average framerate of over 110 frames per second.What more needs to be said ?
[ 本帖最后由 ~DeatHMooN~ 于 23-2-2009 21:51 编辑 ] |
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