PCI Express graphics cards group test review

PCI Express graphics card
Photo of PCI Express graphics cards group test

Although AGP isn’t yet a dead technology for graphics cards, it’s rapidly moving on to the endangered list as PCI Express grows in popularity. Motherboards that support PCI Express have a large chunk of data bandwidth assigned to this new bus which is usually divided up into 20 lanes.

Of these 20 lanes, 16 are dedicated to a slot for a PCI Express 16x graphics card, or PCI-E 16x for short, and there will also be one or two short PCI-E 1x slots. Although we have yet to see expansion cards that use PCI-E, other than graphics cards, you can be sure that they will start to make an appearance during this year.

Athlon 64 and Pentium 4 motherboards that support PCI Express also have conventional PCI slots but you will usually have to choose between AGP or PCI Express graphics as very few motherboards support both types of graphics.

The real strength of PCI Express is that it has a huge capacity for future expansion in data bandwidth whereas AGP has almost reached the limits of the technology. PCI Express has two particularly neat tricks, one for the high end of the market and the other for the low end.

Budget PCI Express graphics cards can be supplied with very little onboard memory, say 32MB, to save on the cost of components and the graphics card can then use system memory for 3D work. Although this is slower than using onboard memory it is perfectly satisfactory for slower graphics chips such as the GeForce 6200.

At the high end we have dual graphics card technologies such as Nvidia’s SLI (Scalable Link Interface) where the motherboard has two PCI Express graphics card slots. The graphics cards work in tandem to either power up to four monitors on the desktop, or they can work in a piggy-backed fashion to double the power of the graphics chip, which will be of interest to gamers.

So let’s have a look at six PCI Express graphics cards to see what’s on offer. Click the ‘NEXT’ link below to find out more.

Coming straight after the Asus Extreme N6600GT, we have to admit that the Leadtek Winfast PX6600TD seems a little dull. It uses the GeForce 6600 GPU, rather than the 6600GT, so the core speed is a mere 300MHz and the memory runs at an effective 550MHz, which makes it more akin to the GeForce 6200 than the 6600GT.

Although the 6600 has the same eight pixel pipelines as the 6600GT, the standard clock speeds are so slow that the Leadtek has a very steep hill to climb. When we ran the Leadtek WinFox utility to overclock the PX6600TD the core speed went up to 400MHz and the memory speed rose to 720MHz which closed the gap on the 6600GT, but you’ll typically find that 6600 cards run regular DDR memory where 6600GTs use DDR3, so if you’re hoping to turn your (£100) 6600 into a (£150) 6600GT you can forget about it as the speed of the memory will always be a limitation.

This means that your £95 buys you a graphics card that supports all of the lovely visual quality features of DirectX 9.0c and Shader Model 3, but you don’t get enough raw graphics power to make the most of the features and Anti Aliasing in particular isn’t really an option when you run a GeForce 6600 as the frame rate drops far too low for comfort.

This makes a mockery of the 146 million transistors humming away inside the Leadtek graphics core as they don’t get the chance to show what they can do.

To our mind the performance of the Leadtek Winfast PX6600TD shows that you should jump directly from a 128MB GeForce 6200 straight to a 6600GT or better, bypassing the 6600 in one stride. A price point just below £100 is very tempting but this graphics card simply doesn’t offer proper value for money.

In this group test we’ve mainly talked about the graphics chips that these cards use, as that is the single most important feature of a graphics card. As we’ve shown, a basic 128MB Leadtek GeForce 6600 costs about the same as a 256MB AOpen GeForce 6200 and outperforms it in every respect, even when the 6200 is overclocked like crazy.

The graphics card manufacturer gets to select the amount and type of memory that it uses, and then it adds a software package and sets the price, but thanks to the transparency of the Internet you’ll find that prices for a particular family of graphics card will rapidly converge. Pick the right graphics chip and you’re half-way home.

The other result of our testing is to show that the balance of power has swung back from ATi to Nvidia, and while those PC owners who don’t want to play intensive games may be more concerned about price than they are about graphics performance, it seems likely that anyone building a PCI Express PC will be at the cutting edge of performance so you would be well advised to focus on the mid-range or high-end graphics cards and to budget at least £100 for your purchase.

Our tests showed that the GeForce 6600 is a good budget chip, but the 6600GT is a superb mid-range graphics chip and the Asus Extreme N6600GT gives you amazing performance for the price.

As the name suggests, the AOpen Aeolus 6200 uses the GeForce 6200 GPU (Graphics Processing Unit) which is the budget chip in the Nvidia family. The 6200 is a cut-down version of the GeForce 6600, so it has four pixel pipelines, rather than eight, so even though the 6200 and 6600 share the same core speed of 300MHz the 6200 is guaranteed to have relatively low performance.

With its previous budget chip, the FX5200, Nvidia further hobbled performance by removing some of the features which allowed the chip to compress image data efficiently, which meant that the FX5200 took a larger performance hit when you enabled image quality features such as FSAA (Full Scene Anti Aliasing) and AF (Anisotropic Filtering), compared to the FX5700.

Nvidia hasn’t gone down this route with the 6200, perhaps because it has realised that the chip simply doesn’t have the performance to run a high resolution above 1,024×768, and neither can it manage to run with FSAA or AF enabled in intensive 3D work. This is almost a truism with budget chips because, let’s face it, if you can play Doom 3 on High Quality settings with a budget graphics card, you won’t need to spend the extra cash on a mid-range or high-end card.

You generally expect to find 128MB of memory on a budget or mid-range graphics card, but AOpen decided to install 256MB of memory on the Aeolus 6200 which adds about £20 to the asking price, so it costs only £6 less than the Leadtek PX6600TD, yet the performance is significantly lower.

The extra memory means that the AOpen is able to complete all of our 3DMark05 tests, including the intensive run at 1,600×1,200 with FSAA and AF enabled, but the score is so low that it only serves to show how unusable a GeForce 6200 is at these settings.

When we ran the Nvidia Coolbits registry update we were able to use Nvidia’s Forceware drivers to overclock the Aeolus by an impressive amount. The core speed rose from 300MHz to 370MHz while the memory speed went from 665MHz to an astonishing 965MHz, and as a result we saw our benchmark results rise by up to 40 percent.

This huge increase doesn’t change the fact that the scores are still low compared to a mid-range graphics card, yet the AOpen is rather expensive for what it delivers.

In the first half of 2004 Nvidia launched its brand new, high-end GeForce 6800 chip and in the summer it followed on with the GeForce 6600 mid-range chip, which is what you’ll find under the heatsink of the Asus Extreme N6600GT.

The GeForce 6600GT is a souped up version of the plain 6600 which typically has a core speed of 500MHz and memory speed of around 1GHz if the card manufacturer uses DDR3, and that’s exactly what Asus has done. This means that the 6600GT runs at the same core and memory speeds as the 6800GT, but as the 660GT has only got eight pixel pipelines and a 128-bit memory controller it can’t compete with its big brother on performance.

It can, however, take the fight to the other cards in this group test, and the Asus beat them all by a healthy margin. Benchmark results are all well and good, but what counts is how the graphics card works in the real world, and here too the Asus impresses. You won’t want to play top games such as Doom 3 with FSAA enabled, but games from a year ago can be played with all of the quality settings turned on, and that’s just amazing for a £149 graphics card.

That was our initial impression, so you can rest assured that when the Asus overclocked to the tune of ten percent we were ecstatic. Mind you, that was with Nvidia’s Coolbits utility, rather than the Asus SmartDoctor software, as we found the latter to be a complete liability.

The Asus is the only graphics card in this group to have the SLI connection that we mentioned in the introduction, so if you have a suitable motherboard with two PCI Express x16 slots you can start your PC build with a single graphics card and then add in a second card at a later date. The Asus is an awesome graphics card for a very fair price.

The Sapphire Hybrid X700 Pro is physically smaller than the X600XT, no doubt because it uses newer, smaller components than the X600XT. The X700 Pro graphics chip uses a smaller fabrication process of 0.11-micron compared to the 0.13-micron process of the X600XT, and the memory chips are the latest small, square BGA modules, rather than the huge old rectangles that were twice the size.

Just like the X600XT, the X700 Pro can trace its roots back to the Radeon 9800, and as you would expect this mid-range chip has eight pixel pipelines and a 128-bit memory controller, just like the GeForce 6600 and 6600GT. Perhaps that’s what Sapphire meant when they called this graphics card the Hybrid.

As the origins of the X700 stretch back so far there’s an issue to consider with regard to DirectX 9 support. The latest Nvidia chips support DirectX 9.0c with Shader Model 3, but at present ATi hardware supports DirectX 9.0b with Shader Model 2.

This isn’t a problem as such as we are unaware that any current games fully exploit DirectX 9.0c but it does leave a question mark hanging over ATi graphics chips as there is the chance that in future some games will look better on graphics cards that use Nvidia chips than they do on ATi, and let’s face it, you’re not spending £135 on a graphics card unless you’re about to play games.

In 3DMark05 the Sapphire card held its own, scoring less than the Asus 6600GT and more than the Leadtek 6600, so performance was pretty much in step with price. It was a different story with Doom 3 where the X700 Pro was beaten by the 6600 and thoroughly trampled by the 6600GT.

This wasn’t encouraging so we used Redline to overclock the Sapphire and were taken aback when it only allowed us to overclock the core and memory by a tiny 14MHz, which suggests that ATi ships the X700 Pro running close to its limits, and in this round of benchmarks the Sapphire was nearly beaten by the Leadtek 6600 in 3DMark05.

When you consider the mediocre performance of the X700 Pro it seems to be crying out for a hefty price cut, and soon.

We only got our hands on the XFX GeForce 6200 for a short time, but we’re glad that we did as this 128MB graphics card is a reference product that is typical of the GeForce 6200 cards that you’re likely to find on sale, regardless of the brand name that they carry.

With a price tag of £70 the XFX is a budget graphics card by any definition, although these days there are even cheaper models on the market such as the XFX 6200 Turbo Cache which only has 16MB of onboard memory, and which connects to the system memory over the PCI Express bus for 3D duties. The XFX 6200 Turbo Cache costs a paltry £45 but we don’t have one to hand so are unable to comment on its performance.

When we plugged the GeForce 6200 into our test PC we saw that the core speed was running at 300MHz, while the memory runs at an effective 550MHz, which is much as we expected. It came as a complete surprise when the XFX trounced the AOpen card in our first round of benchmarks as the AOpen runs its memory significantly faster than the XFX so we were looking forward to overclocking the XFX.

Unfortunately it was not to be as the option for automatically overclocking the card was greyed out in the Nvidia drivers. We had a quick stab at manual overclocking and found that the XFX would run similar clock speeds to the AOpen Aeolus 256MB card in certain tests but would crash out of others, and then we came to our senses and realised that the enthusiast is unlikely to buy a GeForce 6200 in the first place so its overclocking abilities don’t much matter.

The XFX is impressive as it has the ability to play the latest DirectX 9 games such as Doom 3, as long as you keep the resolution down, and you get the benefit of the pixel and vertex shaders, but it’s too slow to make hardcore gaming an enjoyable experience.

On the plus side the XFX GeForce 6200 shows just how far budget graphics cards have advanced in recent times.

The Sapphire X600XT VIVO is the other of the two ATi chipped graphics cards in this group, in this case the Radeon X600XT. Although this is a PCI Express chip, the X600 is based on the Radeon 9600, which in turn is based on the Radeon 9500, and that was a cut down version of the very first DirectX 9 chip of all, the Radeon 9700.

That means that the underlying technology dates back to late 2002 which is a lifetime in the world of graphics chips, and although ATi has carried out extensive development of the silicon to make it more efficient, it is definitely showing its age.

In our benchmark tests the Sapphire X600XT was a little slower in 3DMark05 than the Leadtek GeForce 6600, but in Doom 3 it was comprehensively eclipsed, despite the fact that the Sapphire runs its core and memory 200MHz faster than the Leadtek.

As the workload increases the GeForce 6600 looks better and better while the X600XT limps along behind. Allowing for the fact that the Sapphire has a Video-In feature which adds to the value of the card, the Leadtek and Sapphire pretty much cost the same, and that doesn’t make this card very desirable.

When it comes to overclocking, Sapphire includes a copy of the Redline utility in the box. It’s a cumbersome piece of software that is less user-friendly than Nvidia’s Coolbits, and we would far rather see an overclocking utility that was built into the ATi drivers.

The X600XT didn’t tolerate much overclocking, which is only to be expected as the chip has already been pushed hard by ATi over the last two years. The improvement of some 15 percent was welcome but we were starting from quite a low point so the overclocking couldn’t transform the card, and it looked rather lame compared to the GeForce 6600 which overclocked by about 30 percent.

In short, the Leadtek GeForce 6600 costs the same as the X600XT, it performs better out of the box, and it also returns better results when you overclock it.

Sapphire has done its best to fight against the limitations of the X600XT chip and it includes a software package of Cyberlink PowerDVD for DVD playback and PowerDirector for video editing, but nothing can change the fact that its performance is similar to the XFX GeForce 6200, and that makes the Sapphire X600XT VIVO too expensive.

Our testing with 3DMark05 and Doom 3 was rigorous but it wasn’t extensive, as we could have easily selected six different games, and we would have very likely found that one particular graphics chip had an advantage in your preferred game.

Then the manufacturers would release a new driver version, various games would be patched and updated and we’d have been back to square one.

Accepting this, we bit the bullet and built a test PC with a 3.4GHz Pentium 4 Extreme Edition CPU on an Intel D925XCV motherboard with 925X chipset, 1GB of DDR2 533MHz memory and a WD740 Raptor hard drive, and then ran the latest version of 3DMark05 and Doom 3 at two different resolutions, both with and without FSAA and AF enabled.

pci express graphics card performance test results

pci express graphics card performance test results

pci express graphics card performance test results

pci express graphics card performance test results

Company: Aopen

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