NVIDIA GeForce GTX 260/280 GPUs

Introduction
NVIDIA competes with ATI Technologies - now a wholly-owned subsidiary of microprocessor manufacturer AMD - in the discrete and integrated GPU market. Intel, too, has a significant presence which is currently limited to producing integrated graphics. NVIDIA and ATI design the chips that power graphics cards which are primarily used for playing games. These chips are then built on to a PCB, other necessary components such as memory and cooling are added, and then sold via a number of partners.

Partners include eVGA, XFX, BFG, ASUS, Palit, Inno3D, Foxconn, Leadtek, and ZOTAC, and all purchase NVIDIA-designed GPUs, manufactured in by TSMC in Taiwan, and release cards in both retail and OEM form. Differentiation usually takes place with respect to bundles, warranty, and clock-speeds.

Generally speaking, higher performance requires bigger, more-complicated chips to be engineered, and it's not uncommon for the highest-performing GPUs in 2008 to have more than one billion transistors. NVIDIA designs the high-end chips first, brings them to market, and then derivate down for mid-range and low-end cards. Further, such is the frenetic pace in the GPU market that a brand-new architecture is usually released at least once a year.

As of November 2008, NVIDIA's fastest graphics cards are based around the GeForce GTX 260 and GTX 280 architectures that were first brought to market in June 2008. The GeForce GTX 260 currently costs around £200 and the range-topping GTX 280 around £320. These new GPUs supplant NVIDIA's own 9-series models as company-specific performance leaders, although the 9-series still exists in the mid-range and low-end space.

The purpose of this TekSpek is to define what each GPU family brings to the table in terms of features and performance, and then to briefly compare them with ATI equivalents.

GeForce 9-series
The bulk of NVIDIA's GPU revenue is derived from sales of its DX10-compatible GeForce 9-series GPUs that can trace their architectural lineage back to the GeForce 8800 GTX, launched in November 2006.

The current line-up comprises of the GeForce 9200 (£30); 9400 (£40), 9500 (£60), 9600 (£80), and 9800 (£90+) families. The higher the product-family number, the higher the performance, generally. Each family is further sub-divided into additional models that saturate every price-point, and we've listed the basic pricing in parenthesis.

A number of GPUs are also available in mobile form, for laptops, and they're usually added to mid- and high-end laptops as dedicated gaming cards.

The majority of 9-series cards are based on the PCIe bus - the method by which they plug into the motherboard - and models above a GeForce 9600 require additional power from the computer's power-supply unit, by attaching to a six-pin header on the card.

Graphics cards need to do more than just render games right now, and all 9-series cards help in processing video that's displayed on your screen. Playing back Blu-ray or high-definition video requires extensive processing power as the codec used to encode the content is decoded, and all 9-series cards carry what is known as the PureVideo engine that helps offload most of the work from the system's CPU.

Newer cards are endowed with the PureVideo 3 engine that provides full assistance in high-definition decoding of both H.264 and VC-1 codecs, matching what ATI has been offering for a while with its 4-series GPUs.

Basic performance analysis intimates that a 128-core GeForce 9800 GTX+, currently e-tailing for around £110, provides an average frame-rate of >30fps when running modern, fast-paced games at 1,280x1,024 and with high degrees of image-quality enhancement.

GeForce GTX 260/280
NVIDIA's flagship GPU architecture takes the best bits from GeForce 9 and adds in more oomph by, in the main, adding more processing cores and memory bandwidth - the two parameters of modern-day performance.

Talking numbers for a moment, the also-DX10-compatible GeForce GTX 260 is equipped with 192 cores and has around 112GB/s of card-based bandwidth, run via a 448-bit memory interface. A newer model, dubbed 216-core, adds another processing block - 24 cores - for slightly higher performance, but keeps most other parts of the GPU the same.

Generalising again, GeForce GTX 260 216-core performance approaches 2x that of a GeForce 9800 GTX+ at higher resolutions, supplied by a wider, leaner architecture.

At the very top end sits the GeForce GTX 280 that can be thought of as a faster GTX 260 - the basic guts of the GPU are the same. The 240-core processor is clocked in at higher speeds and also has more bandwidth, around 142GB/s, and just like GTX 260, a further two cards can be added, forming 3-way SLI, for even-higher performance.

The competition
Inevitably, the competition for discrete graphics cards lies with ATI, and, of late, the company has been releasing newer GPU architectures at a faster pace than NVIDIA. ATI's current HD 4800-series scales from £90 through to £350 and provides stiff competition at every price-point.

In terms of numbers, ATI's designs, at a particular price, generally have more pure power and a better multimedia feature-set - on-board HDMI support, for example - but NVIDIA's latest drivers - release 180 - help close the gap. Put simply, competition is so fierce that neither company can afford to design a bad GPU, and spending £100 on any GPU, irrespective of manufacturer, will yield competitive performance.

Summary
NVIDIA currently segments its discrete desktop GPUs into the 9-series and GTX 2x0-series, with the former plying all price-points up to around £150 and the latter taking over and rising all the way to £350 for super-overclocked models.

GeForce GTX 260/280 is a fundamentally better design than the 9-series and should your budget extend to £150 we'd recommend going for the former.

However, stiff competition from ATI makes the overall choice that much more complicated, with the burgeoning GPGPU (general-purpose computing on graphics processing units) bringing a whole new dimension to bear.

Pragmatically, potential purchasers should look at more than just basic clock-speed when evaluating competing products, however, as warranty and after-sales support is just as important, if not more so.