Rumour: GeForce GTX 460 specs revealed

Now that the Fermi production lines are finally in full swing, all sorts of rumours are starting to pop up concerning this summer's mid-range parts. We've already seen plenty of talk about the GeForce GTX 460, but the latest rumours show that at least one gossip talker is barking up the wrong end of the stick.

Tech site Expreview claims that it's snapped a driver screenshot from a machine with a GeForce GTX 460 installed. Using Nvidia's 258.41 driver, the control panel apparently shows the detailed specs of the new GPU.

As previous rumours had predicted, the chip appears to have a 192-bit memory interface, with which it addresses 768MB of GDDR5 memory. The screenshot shows that the memory is clocked at 1,800MHz (3,600MHz effective), while the GPU is clocked at 675MHz with 1,350MHz stream processors.

However, the driver also reports that the chip has 336 stream processors, which turns over some previous rumours about the GPU.

Nvidia's current GF100 architecture groups stream processors into batches of 32, as we saw when the GeForce GTX 480 only featured 480 stream processors, rather than the 512 that it was originally supposed to have. However, if you divide 336 by 32 then you get 10.5, which means that this chip probably divides the stream processors into groups of 16 instead.

This makes sense, given that earlier rumours stated that the GeForce GTX 460 would feature Nvidia's new GF104 graphics chip, rather than the GF100 that forms the basis of the current Fermi line-up. The problem is that these previous rumours put the maximum count of GF104's stream processors at 256.

Meanwhile, other tech sites say that the GTX 460 will feature 240 stream processors. Again, this is a number that can be divided by 16, but not 32.

Someone's got the information wrong somewhere along the lines, but we reckon there's some truth hidden in all of it. If we were to hazard a guess, we'd say that GF104 will enable stream processors to be grouped in batches of 16, enabling chips with 240, 256 and even 336 stream processors.

It certainly seems more likely that the GTX 460 will have 336, rather than just 256 or 240 stream processors. When you consider that the GTX 465 has 352 stream processors at its disposal, a jump of 112 stream processors would be pretty big for a drop of just five in the model number.

Unsurprisingly, Nvidia told us that it couldn't comment on "rumoured or unannounced products," so we'll have to wait and see. The GTX 460 is widely expected to be heading for a release next month, so we shouldn't have to wait long.