Extreme Graphics


Sunday, November 19, 2006
It's quite often that we find ATI and Nvidia rebadging their products. As it happens many times, relaunching an existing graphics card with a new name, tweaked settings and a better price point can do wonders. While there are many examples of successfully rebadged products, there are also those that have gone wayward.

Today we will be taking an in-depth look into two of those "new" products, as both use parts handed down from existing current generation products.

Take the Nvidia GeForce 7900GS, for example. This recently released graphics card is based on the original G71 architecture, which made its debut past March in the form of the GeForce 7900GTX. The 7900GT was the second graphics card to be built around the G71 core, followed by the 7950GT, and now the 7900GS. The 7950GT is nothing more than a supped up version of the 7900GT, though the added performance of the new 7950GT does justify the added cost. The 7900GS, on the other hand, might still be based on the same architecture, but it is a more unique product created to fill the void between the 7950GT and the 7600GT.

With a sub-$200 price tag, the GeForce 7900GS has indeed made a great job filling the gap, in fact, prior to the release of the competing Radeon X1950 Pro, there was nothing that could really compete with it in this price range. Therefore in an effort to regain some prime real-estate back, ATI gave life to this new Radeon family member.

Like the 7900GS, the X1950 Pro appears to be a brand new product, and it even goes by a new code-name “RV570”, but do not let this fool you. The specifications of the X1950 Pro are suspiciously close to that of the X1900GT, which was a failure in my eyes. Perhaps that's a little harsh comment regarding the Radeon X1900GT, however at the time of its release the product was slower than existing X1800XT and 7900GT products, yet it was significantly more expensive. For that reason I wrote the X1900GT off early, and it never really came back to redeem itself, until now of course. The new X1950 Pro features the same core clock frequency as the X1900GT, faster memory (180MHz higher) and the same amount of rendering pipelines. However, while the X1900GT made its debut at $300, the X1950 Pro will be available at the much more affordable price of $200. Although on paper the specifications of the X1950 Pro and 7900GS seem to be quite different, there are a few similarities we can talk about. For starters, both products come armed with 256MB GDDR3 memory, though the X1950 Pro has a 60MHz clock advantage here. As usual, the ATI card also carries the higher core clock frequency (125MHz advantage). However, where the X1950 Pro loses is in the amount of physical pipelines as it features just 12, whereas the 7900GS sports a total of 20. Both graphics cards feature a single texture mapping unit, and the X1950 Pro utilizes an additional vertex processing unit. Once all that has been taken into account, the X1950 Pro ends up with just 2GB/s more memory bandwidth on its favor (a ~5% advantage).

Perhaps, the biggest strength of the GeForce 7900GS is its overclocking ability. Manufacturers are already shipping 7900GS cards with a 30% rise in core frequencies and up to 10% boost in memory speeds. In many cases I found this to result in performance increases that went anywhere from 15% and up to 30%. Given the 7900GS already delivers exceptionally good value for a sub-$200 graphics card, a potential performance increase of 30% is very impressive.

This is where I believe the war between the GeForce 7900GS and the Radeon X1950 Pro will be settled. Depending on the games used for comparison, the performance can go either way as we have seen time and time again. This means that unless the Radeon X1950 Pro is able to achieve a reasonable boost in performance through overclocking, it might fall short, or will it?

Benchmarks: 3Dmark2006, X3: Reunion


Test System Specifications
- Intel Core 2 Duo E6700 (2.66GHz) LGA775

- Corsair PC2-6400 2GB DDR2

- ASUS P5W DH Deluxe (Intel 975X)

- Seagate 250GB 7200RPM (Serial ATA II)

- Nvidia GeForce 7900GS (256MB)
- ATI Radeon X1950 Pro (256MB)

Software
- Microsoft Windows XP Pro (SP2)
- Nvidia Forceware 91.47
- ATI Catalyst 6.10
- Intel System Drivers 7.2.2


At their default clock speeds, 3Dmark2006 placed the Radeon X1950 Pro well ahead of the GeForce 7900GS giving it a 21% performance advantage at 1600x1200. Through overclocking the X1950 Pro became just 3% faster while the 7900GS catapulted into the lead with a 27% performance gain.


Previous tests using X3: Reunion have shown that this engine tends to favor ATI-based graphics cards. That being the case I was not surprised to find the Radeon X1950 Pro defeating the GeForce 7900GS. However, I was surprised about the degree to which the X1950 Pro defeated the 7900GS, at 1600x1200 the Radeon was 40% more powerful.

The X1950 Pro once again failed to gain much ground through overclocking, and as a result the 7900GS was able to close the margin down to 22%.


Benchmarks: Far Cry, F.E.A.R

The Radeon X1950 Pro also does very well in Far Cry as it defeated the GeForce 7900GS by 40% prior to overclocking. Once the cards were overclocked this margin was reduced to 24%, which is still obviously a very significant win for the X1950 Pro.


F.E.A.R is a very demanding game, and when FSAA 4x + Aniso 16x quality settings are enabled, good frame rates are hard to come by. That being the case we will go off the 1024x768 performance where the Radeon X1950 Pro was 45% faster than the GeForce 7900GS. Once again overclocking did reduce the performance margin to 26% in favor of the Radeon, still a very strong lead.


And the best buy is:

Both the ATI Radeon X1950 Pro and the Nvidia GeForce 7900GS are $200 graphics cards, at least this was their suggested retail price at launch. Currently however, GeForce 7900GS cards can be found for as little as $180, while most X1950 Pros will set you back something closer to the $220 mark. As it commonly happens, we expect that as the X1950 Pro establishes better and more samples hit shelves, its price will drop closer to that of the GeForce. This being the case for now though, even with the price premium, I believe buying the Radeon X1950 Pro over the GeForce can easily be justified. The performance of the X1950 Pro is just that good, despite offering poor overclocking capabilities. Clocked at its default frequencies the X1950 Pro was faster than the overclocked 7900GS in X3: Reunion, Far Cry and F.E.A.R making it faster in three of the five games tested. Then when it came to games such as Prey and Quake 4, the 7900GS was faster though the performance margins were very slim.

The overclocked GeForce 7900GS configuration did its best to hang in there, and at the lowest tested resolution of 1024x768 it did quite well against the X1950 Pro. As the resolution was increased, so did the performance gap, and by the time we hit 1600x1200 the X1950 Pro was leading the pack.

Just a month ago we found ourselves testing the 7900GS as the new king in the $200 price bracket as it bridged the performance gap between the 7900GT and the budget performance king the 7600GT. Only a month later, the 7900GS has been knocked from its perch by the Radeon X1950 Pro which has now established itself as the most dominant $200 graphics card on the market. Now ATI just needs to get the X1950 Pro out there in numbers, and I am sure this is what will happen in the coming weeks.

Friday, November 17, 2006



Coke or Pepsi? Intel or AMD or in this case ATI or NVIDIA? It’s all about choices. Like always, the competition is fierce between the Santa Clara based NVIDIA and the red team from Ontario. This time it’s NVIDIA’s turn, they just released their GeForce 8800 series, signifying, you guessed it, another speed increase. Though, I’m left wondering what they are going to do after the 9xxx numbers are used. NVIDIA has come a long way from the old GeForce FX 5800 “Dustbuster” days, remember that one?

The GeForce 8800 series is getting a lot of attention due to its lead over ATI in many graphics benchmarks, in some cases beating ATI's cards in a Crossfire setup. But as usual, you don't get to keep the performance crown that long in the graphics world, as either ATI or NVIDIA are always cooking up something to dethrone the other.

The GeForce 8800 series codenamed G80 is DirectX 10 compliant and comes in two flavors: GeForce 8800GTX and 8800GTS.

The 8800 GTX card has all architectural features enabled, including the128 stream processors running at 1.35GHz, the GPU clocking in at 575MHz and a 384-bit path to memory. The amount of built-in memory is an amazing (for graphics cards at least), 768MB of Samsung GDDR3 clocked at 900MHz (1800MHz effective being DDR). This card will be priced at $599, but you can expect higher prices then the suggested MSRP. For those of us with less money to burn, NVIDIA also created the 8800 GTS variant featuring a 500MHz GPU, 1.2GHz stream processors, 640MB of GDDR3 memory running at 800MHz, and the same set of output ports and capabilities as the GTX. The GTS is basically uses a cut-down version of the G80 with some units disabled, equipped with 96 stream processors, five ROP partitions, and a 320-bit memory path. All these lesser capabilities can be seen in the lower price of $449.

The GTS variant might offer lesser performance but it offers something that GTX can’t: a shorter board and less power-hungry. The GTX will actually need dual six-pin PCIe power connectors not to mention that it looks absolutely huge!!!

A new graphics card from NVIDIA also signifies getting a new mascot. It started with the now famous Dawn demo and it continued with Nalu the mermaid and the high priestess Luna. With the 8800 series they are now using Adrianne Curry, a real-life model. The previous tech demos used fictional characters.



The Architecture

NVIDIA played it safe with this design by using the tried and true 90nm process; this allows for increased yields, but on the other hand a very large chip.

The G80 architecture that the 8800 series is based on uses a unified architecture that merges both vertex and pixel shaders into a single tank of floating-point processors.

On the simplified diagram of the G80 the green squares the Stream processors; the G80 has a total of 128 on the GTS version. Unlike in traditional architectures the stream processors aren't vertex or pixel shaders, but generalized floating-point processors capable of operating on vertices, pixels, or any type of data that it gets thrown at it. These Stream Processors operate at an astonishing 1.35GHz.

Below the Stream Processors we find the ROP partitions with their L2 cache. These ROP partitions have in total a 384-bit path to memory. Also noteworthy is the fact that NVIDIA chose a separate chip to drive displays

I also expect a slew of lower priced midrange and low-end cards based on this architecture to appear soon
FIRESTREAM BOARDS ARE hitting the world of research and development, but they're not flying under the ATI banner. Named "AMD Stream Processor", these babies pack a peak power of 375 GFLOPS, easily slaying any single CPU in the world today. Or tomorrow, for that matter.


As you can see in the picture above, the board is your typical ATI Radeon X1900 with the old and loud cooler, but now with AMD branding. We know that the colour of upcoming graphics products is still red, so perhaps AMD won't bring Graphzilla's colour to the PCB level. The board is only a rebranding of never released FireSTREAM boards, which were ready for launch in late September, but AMD wanted to do the rebranding thing first.

The "Stream Processor" comes running at a clockspeed similar to that used on X1900XT series of cards. The board packs 1GB of GDDR3 memory - 512MB located at the front and 512MB at the back of the PCB.

On two pictures below, you can see how the "ATI FireSTREAM Enterprise Stream Processor" originally looked:


Since Nvidia already uses the term "Stream Processor" as a description for its scalar Shader units, we're tempted to suggest that AMD's marketing might have missed the boat.

We can now conclude that the acquisition is over and that the ATI brand is dead after all, as we wrote over three months ago.

AMD decided to do an Nvidia/3dfx and the case is closed. Regardless of what some AMD or ATI execs might be saying, the actions they took with their partners and employees of ATI speak for themselves.

We have heard that even the Radeon brand is in jeopardy, because some AMD folk are constantly downplaying the value of ATI and related brands. But we will be addressing this and disclosing all of the nitty and gritty next week. µ