Overclocking and Test Setup

Overclocking

What we were more eager to see though was how that affected our overclocking!  The stock frequencies on the BFG 7800 GT OC WC are already running over what the NVIDIA specifications are by quite a bit.  Keeping in mind the reference clocks on the 7800 GT from NVIDIA are 400 MHz core and 1.0 GHz memory:

BFG 7800 GT OC Water Cooled Review - Graphics Cards 42

Stock speeds

BFG overclocks the GT 70 MHz on the core and leaves the memory alone out of the box.  That is a 17.5% increase in clock speed. 

BFG 7800 GT OC Water Cooled Review - Graphics Cards 43

Auto overclocking

Just by hitting the ‘Detect Optimal Frequencies’ button in the driver, we were able to get these additional overclocked results.  That is a 20 MHz faster core than stock and 90 MHz faster memory clock over the stock settings and a 22.5% increase over reference core clock and 9% increase on memory clocks.  Not too bad!  But what could we get with a little manual tweaking?

BFG 7800 GT OC Water Cooled Review - Graphics Cards 44

Manual overclocking

That’s pretty impressive, an additional 10 MHz on both the core and memory clock give us a 500/1.10 total overclock.  That gives us a 25% faster core over the reference cards and a 10% faster memory system than reference.  No doubt that will translate into some serious performance. 

Being as we know the 7800 GT core and the 7800 GTX core share the same basic architecture with the only difference being fewer pipelines on the GT, it makes sense that we would be able to see overclocks like this off of a part with obviously high yields.  Surely BFG is sifting through their supply of 7800 GT chips and putting the premiere ones on these water cooled units, but I can’t say for sure.  In any event, this water cooled 7800 GT is a real enthusiast card.

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

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. 

For our review I decided to compare the BFG 7800 GT OC WC against the other 7800 GT retail card we have reviewed: the XFX 7800 GT OC.  This card runs at 450 MHz core out of the box, so even in standard clock modes the BFG holds a 20 MHz advantage.  Of course I also included results from the top overclocked configuration as well.

Being as so few of the retail cards we are seeing for sale of the 7800 GT actually use reference clocks, I saw no reason to include a reference card in this comparison. 

NVIDIA Test System Setup

GPUs

BFG 7800 GT OC Water Cooled (470/1.00)
BFG 7800 GT OC Water Cooled (500/1.10)
XFX 7800 GT (450/1.05)

Processor

Athlon 64 FX-55

Motherboard

Gigabyte K8NXP-SLI

Chipset Driver

6.53

Memory

2 x 512 MB Corsair 3200XL

Memory Timings

2.0 2-2-5

Sound Card

Sound Blaster Audigy 2

Hard Drive

Maxtor DiamondMax 10 300 GB

Operating System

Windows XP Professional SP1

NVIDIA Driver

77.77

Software tested:

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