Introduction

With ATI’s not so secret plans to launch a slew of new graphics cards later this month hitting the web, including the Radeon X1950 XTX and the rumored X1950 Pro, as well as the X1650s and X1350s, NVIDIA has decided to launch a preemptive attack on ATI to spoil their plans.

NVIDIA’s attack will come in two waves: first, for the mainstream market, NVIDIA’s prepped the GeForce 7900 GS 256MB, this is the GPU we’ll be taking a look at in today’s article. The GeForce 7900 GS carries a $200 price tag and is loaded with features, but more on this later.

The GeForce 7950 GT

Sitting above the GeForce 7900 GS in NVIDIA’s refreshed lineup is the GeForce 7950 GT. The GeForce 7950 GT takes the $300 spot currently occupied by the GeForce 7900 GT, and sports a 550MHz core clock speed with 512MB of GDDR3 memory running at 700MHz (1.4GHz effective). With a 550MHz core clock speed, the GeForce 7950 GT runs a full 100MHz faster than the GeForce 7900 GT it replaces on the graphics core, and just 100MHz shy of the GeForce 7900 GTX, while its memory is 140MHz faster than the 7900 GT and 100MHz below the 7900 GTX.

The GeForce 7950 GT is also equipped with two dual-link DVI connectors and all 7950 GT cards will carry full HDCP support.

NVIDIA GeForce 7950 GT reference board

The 7950 GT

As you can see in the images, the GeForce 7950 GT will continue to reside in a single-slot package, in fact NVIDIA’s reference board appears to borrow the same reference cooling used on the 7900 GT. As a result, going from the GeForce 7900 GT to the 7950 GT should be a smooth transition for board manufacturers, all they’ve got to do is swap out the core and memory, and integrate the extra crypto-ROM chip to store the card’s HDCP key. With the 7950 GT officially replacing the 7900 GT, look for GeForce 7900 GT cards to drop in price down to the $200-$300 range before slowly disappearing. The GeForce 7950 GT will hit store shelves next week on September 14th, taking on ATI’s recently announced Radeon X1900 XT 256MB directly.

G71 gets cheaper: the GeForce 7900 GS

Pegged just below the GeForce 7950 GT will be the GeForce 7900 GS, NVIDIA’s sixth GPU to utilize their 90-nm G71 graphics chip. The 7900 GS retains all the key features found in more senior G71-based GPUs like the GeForce 7950 GT and GeForce 7900 GTX, only for the GeForce 7900 GS NVIDIA deactivates one of the GPU’s six pixel shading quads, effectively disabling four pixel shading units in the process. This brings the total number of active pixel shaders in the GeForce 7900 GS down to 20, in comparison the 7900 GT/GTX and GeForce 7950 GT all feature 24 pixel shaders. NVIDIA also disables one vertex shader in the GeForce 7900 GS, leaving seven vertex shaders active (in comparison the other G71 cards feature eight vertex shaders).

NVIDIA GeForce 7900 GS reference board

Top of the 7900 GS reference card

Clock speeds for the GeForce 7900 GS carry over unchanged from the 7900 GT, the graphics core is clocked at 460MHz while the board’s memory runs at 660MHz (1,320MHz effective). In terms of connectivity, like the other GeForce 7900 cards the GeForce 7900 GS is outfitted with two dual-link DVI connectors but unlike the 7950 GT, HDCP support is an optional feature – it will be up to NVIDIA’s board partners to determine which (if any) of their GeForce 7900 GS cards will offer full HDCP support. Among the board partners we polled, most of them don’t plan to offer HDCP support for their first crop of GeForce 7900 GS cards, but there are HDCP-compliant GeForce 7900 GS cards out there. You’ll have to read the fine print closely if this feature is important to you.

Back of the card

7900 GS installed

Besides its G71 graphics core, the most attractive part about the GeForce 7900 GS is without a doubt its price. The board carries an MSRP of $199 and is outfitted with 256MB of GDDR3 memory. In terms of availability, unlike the GeForce 7950 GT, the 7900 GS is available now, retailers are selling boards as we speak from a variety of NVIDIA’s board partners. (In fact, we’ll be taking a closer look at the first wave of partner boards on the next page.) With its $200 price tag, the GeForce 7900 GS is expected to do battle with ATI’s Radeon X1800 GTO and X1900 GT as street prices on both cards are in the same price range as the 7900 GS (as of right now, the lowest PriceGrabber listings for the X1800 GTO are $199.99, while the X1900 GT starts at about $209.99).

The following chart summarizes how the GeForce 7900 GS and 7950 GT compare to the rest of NVIDIA’s high-end lineup, as well as competing cards offered by ATI.

GPU Comparison
	GeForce 7950 GX2	GeForce 7900 GTX	GeForce 7950 GT	GeForce 7900 GT	GeForce 7900 GS	Radeon X1900 XT 256MB	Radeon X1900 GT	Radeon X1800 GTO
Core Clocks	500	650	550	450	450	625	575	500
Pixel Shaders	24x2	24	24	24	20	48	36	12
Vertex Shaders	8x2	8	8	8	7	8	8	8
Texel Fill-rate (Mtexels/s)	24000	15600	13200	10800	9000	10000	9200	6000
ROPs	16x2	16	16	16	16	16	12	12
Effective Memory Clock	1200	1600	1400	1320	1320	1450	1200	1000
Memory Bandwidth (GB/s)	76.8	51.2	44.8	42.2	42.2	46.4	38.4	32