Faster And Cheaper
A manufacturing process shrink is a lot to get excited about for both vendors and their customers, as the change normally leads to increased performance and efficiency, while reducing production cost by increasing the number of units produced per wafer. But the eventual benefit to design firms often comes at a huge up-front cost, since significant alterations normally result in bugs that need to be fixed before a full production run can begin. Each test run costs hundreds of thousands of dollars, so it pays to get things right the first or second time. Production delays are an even costlier problem when new architecture is involved, which is why Nvidia normally updates its current products before introducing any new ones.
Today’s updated product, the GeForce GTX 285, makes the typical promises of improved performance and efficiency compared to the GeForce GTX 280 on which it is based. Let’s take a quick look at how it compares to other high-end solutions.
| GeForce GTX 285 | GeForce GTX 280 | GeForce GTX 260 | GeForce GTX 295 | Radeon HD 4870 X2 | |
|---|---|---|---|---|---|
| Manufacturing Process | 55 nm TSMC | 65 nm TSMC | 65 nm TSMC | 55 nm TSMC | 55 nm TSMC |
| SPs | 240 | 240 | 216 | 480 Total | 1,600 |
| Core Clock | 648 MHz | 602 MHz | 576 MHz | 576 MHz | 750 MHz |
| Shader Clock | 1,476 MHz | 1,296 MHz | 1,242 MHz | 1,242 MHz | 750 MHz |
| Memory Data Rate | 2,484 MHz | 2,214 MHz | 1,998 MHz | 1,998 MHz | 3,600 MHz |
| Frame Buffer | 1 GB | 1 GB | 896 MB | 1,792 MB Tot. | 2 GB Tot. |
| Memory Bus Width | 512-bit | 512-bit | 448-bit | 448-bit x 2 | 256-bit x 2 |
| ROPs | 32 | 32 | 28 | 56 Total | 32 Total |
| Price | $380 | ~$340 | ~$260 | ~$500 | ~$430 |
The GeForce GTX 285’s most noticeable performance-oriented improvement is an increase in GPU clock speed of around 8%. The memory clock increase–while much larger at 12%–is likely not as important for performance. GeForce GTX 295 graphics units get two of these processors, although each one is handicapped with slower GPU speed, memory speed, and memory bus width. Meanwhile, AMD earns bragging right for both GPU clock and memory data rates, but only because less-complex graphics processors typically clock higher and GDDR5 memory uses a quad-data rate bus.
The specific card in today’s review is a special "XXX" sample of XFX’s GeForce GTX 285, model GX-285N-ZDDF, sporting a core clock of 670 MHz and GDDR3-2500. The larger numbers look more impressive than they are, since these are less than 4% GPU and 1% RAM above the reference specification, so we’ll split the difference and consider it a likely 2-3% average improvement over base speed.
In addition to the basics, XFX includes a door tag, the game Far Cry 2, a DVI-to-HDMI adapter, and an S/PDIF breakout cable. The breakout cable connects a motherboard’s internal S/PDIF audio output to an input adjacent to the card’s power connections, and the combined audio/video signal can be accessed though the output of the HDMI adapter. While this method has been available on Nvidia products for several generations, many previous packages did not include the special cable.
