What do we compare it to?

Today’s release is the first product to be based on the ATI CrossFire technology and is based solely around the X850 and X800 product family.  ATI was very clear with the press that by no means was this release going to be the fastest GPU configuration available and thus was not meant to compete with the 7800 GTX or GT graphics chips from NVIDIA.  ATI has new pricing on the X850 and X800 master cards that puts them at or below the cost of the 6800 Ultra, GT and 6800 vanilla configurations as those are the main competitors of this release of CrossFire. 

In a few days, we’ll see the R520 and CrossFire configurations for that as well that WILL be competing with the top card from NVIDIA, so that will surely be a good show to watch for!

For our review of the X850 XT CrossFire Edition, choosing the test setup that would be most beneficial to our readers was important to decide.  I ended up going with two sets of graphics on our article; one that compares the X850 XT in single GPU mode against the X850 XT in multiple GPU mode and against the 6800 Ultra in SLI mode.  These graphs will show us how well the ATI CrossFire technology scales as well as comparing the top performance of ATI and NVIDIA at these price levels.  The other set of graphs shows the X850 XT CrossFire mode, the 6800 Ultra SLI mode and a 7800 GTX in a single GPU configuration.  Why did I throw that into the mix?  It all comes down to pricing…

Pricing Reasoning

Let’s presume that you own a PCI Express motherboard (non-SLI and non-CrossFire) and a PCI Express graphics card.  Your choices for an increase in GPU performance then depend on your current GPU and the upgrade options you have available. If you own an ATI X850 or X800 card, then you can either choose to a) buy a CrossFire motherboard along with an X850/X800 master card to complete a CrossFire setup or b) buy an NVIDIA GeForce 7800 GTX card.  Both of these options should theoretically cost you about the same ($500-$600 in price).  If you currently own an NVIDIA 6800 GT or Ultra card, then you have very similar options of a) buying an SLI motherboard along with another 6800 GT/Ultra for an SLI setup or b) buying a GeForce 7800 GTX.  And again, both of the available options cost about the same ($500-$600 in price).

Now, if you already own an SLI motherboard and an NVIDIA 6800 series card, then obviously going with an SLI setup is going to be a much cheaper option.  If you actually own an SLI board but an ATI graphics card, then your options are again as described above.  And since no one yet owns any CrossFire motherboards, that scenario should just be passed over.

With NVIDIA currently the only GPU vendor having a next generation part available faster than the X850s and 6800s, it would appear that the most noteworthy comparison today is going to be SLI and CrossFire against a single 7800 GTX.  We assume then that users who are starting ‘fresh’ (with either no PCIe graphics card or a new system) would be looking more towards a new GeForce 7800 or R520 setup and wouldn’t really be interested in building a new system based on the GeForce 6 series or X850 series right now.  I am sure there are going to be exceptions to that, so we are of course still comparing the performance of SLI against that of CrossFire directly as well as to the 7800 GTX.

Testing Methodology

Graphics card testing has become the most hotly debated issue in the hardware enthusiast community recently.  Because of that, testing graphics cards has become a much more complicated process than it once was.  Where before you might have been able to rely on the output of a few synthetic, automatic benchmarks to make your video card purchase, that is just no longer the case.  Video cards now cost up to $500 and we want to make sure that we are giving the reader as much information as we can to aid you in your purchasing decision.  We know we can’t run every game or find every bug and error, but we try to do what we can to aid you, our reader, and the community as a whole.

With that in mind, all the benchmarks that you will see in this review are from games that we bought off the shelves just like you.  Of these games, there are two different styles of benchmarks that need to be described.

The first is the “timedemo-style” of benchmark.  Many of you may be familiar with this style from games like Quake III; a “demo” is recorded in the game and a set number of frames are saved in a file for playback.  When playing back the demo, the game engine then renders the frames as quickly as possible, which is why you will often see the “timedemo-style” of benchmarks playing back the game much more quickly than you would ever play the game.  In our benchmarks, the FarCry tests were done in this matter: we recorded four custom demos and then played them back on each card at each different resolution and quality setting.  Why does this matter?  Because in these tests where timedemos are used, the line graphs that show the frame rate at each second, each card may not end at the same time precisly because one card is able to play it back faster than the other — less time passes and thus the FRAPs application gets slightly fewer frame rates to plot.  However, the peaks and valleys and overall performance of each card is still maintained and we can make a judged comparison of the frame rates and performance.

The second type of benchmark you’ll see in this article are manual run throughs of a portion of a game.  This is where we sit at the game with a mouse in one hand, a keyboard under the other, and play the game to get a benchmark score.  This benchmark method makes the graphs and data easy to read, but adds another level of difficulty to the reviewer — making the manual run throughs repeatable and accurate.  I think we’ve accomplished this by choosing a section of each game that provides us with a clear cut path. We take three readings of each card and setting, average the scores, and present those to you.  While this means the benchmarks are not exact to the most minute detail, they are damn close and practicing with this method for many days has made it clear to me that while this method is time consuming, it is definitely a viable option for games without timedemo support.

The second graph is a bar graph that tells you the average framerate, the maximum framerate, and the minimum framerate.  The minimum and average are important numbers here as we want the minimum to be high enough to not affect our gaming experience.  While it will be the decision of each individual gamer what is the lowest they will allow, comparing the Min FPS to the line graph and seeing how often this minimum occurs, should give you a good idea of what your gaming experience will be like with this game, and that video card on that resolution.

Our tests are completely based around the second type of benchmark method mentioned above — the manual run through.

Test System Setup

Because of the way we benchmark our graphics cards and how we display that information, getting more than three GPUs on a single graph is nearly impossible and degrades the quality of the graphs enough to make them almost useless.  Because of this, I decided to break up our data into two sets of graphs: one to compare a single X850 to CrossFire X850s and to 6800 Ultras in SLI.  The other graph compares the dual GPU setups to a single 7800 GTX.

Each set includes a line graph and a bar graph.  The line graph still shows the performance over the span of time of the benchmark and the bar graph shows the data in a min/max/avg format that many readers like to see and are more comfortable with. 

You’ll also notice that I only tested the games we benchmarked at the 1600×1200 resolution.  While some gamers may not have the ability to run at that high of a resolution, it is really a silly notion to buy a $600 graphics card and NOT run at the highest frame rate possible that gives acceptable performance.  With the new 7800 GTX, and even the 6800 Ultra and X850 XT PE in most cases, these cards benchmarked are fast enough that 1600×1200 isn’t in doubt and thus I feel that gamers OUGHT to be playing at this level having spent the money they did on such products.  I am open to comments on this issue as well, so please, let me know how you feel on it.

Test System Setup

GPUs

GeForce 7800 GTX
GeForce 6800 Ultra (x2 in SLI)
ATI X850 XT CrossFire Edition
ATI X850 XT (x2 in CrossFire Mode)

Processor

Athlon 64 FX-55

Motherboard

Gigabyte K8NXP-SLI
ATI Radeon XPress 200 Reference board

Chipset Driver

SLI – 6.53
CrossFire – 5.8

Memory

2 x 512 MB Corsair 3200XL

Memory Timings

2.0 3-3-6

Sound Card

Sound Blaster Live! Value

Hard Drive

Maxtor DiamondMax 10 300 GB

Operating System

Windows XP Professional SP1

NVIDIA Driver

77.77

ATI Driver

5.8 CCC

Software tested:

  • Doom 3 v1.3
  • Far Cry v1.3
  • Half-Life 2 Engine 7 (two maps)
  • EverQuest 2
  • Battlefield 2
  • 3DMark05
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