Nvidia's GeForce GTX 285: A Worthy Successor? : 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.



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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.