ASUS GTX 460 TOP 768MB
After the launch of the GF100 that’s found on the GeForce GTX 480, 470, and 465 cards, it became apparent that some changes were necessary in order to not only streamline the architecture but also improve upon some of the issues that became apparent; namely, it’s size and heat output. The market segment that would buy a card like might not care as much and are willing to accept the downsides in order to achieve better performance. However, as we move down the price ladder, those issues simply aren’t acceptable, particularly when ATI’s Radeon cards don’t have those issues.
So in order to capitalize on the more lucrative market, Nvidia had to look at changes for the GF104 architecture in order to better compete. Simple down-scaling wouldn’t work in this case because as you decrease the streaming processors, the texture units would drop considerably, leaving us with a neutered card. Instead, Nvidia enhanced the stream processors in a reorganized architecture, leaving us with two Graphics Processing Clusters with four Simultaneous Multiprocessors each, along with 48 CUDA cores each.
When we look a bit closer at the SM in this revamped GF104, it becomes apparent that this increased CUDA cores also has double the number of dispatch units (now four), and double the number of texture units. So the original concern of having too few texture units if the stream processors were reduced are now alleviated, giving us a more compact design that packs in more texture units.
Lastly, we know that Nvidia has been pubilicizing tessellation performance as a key advantage in their products over the competition. What we see here now is that the PolyMorph Engines have changed as well, leaving us with 41.5 cores per tessellation engine, up from the 30 we saw in the GTX 480. What this means is that even though the GTX 460 is a few rungs down on the performance ladder, it should be surprisingly adept at DX11 games which predominantly feature tessellation effects.
It must also be mentioned that Nvidia is launching two versions of the GTX 460, in the form of a 1GB card as well as a 768MB card. The 1GB carries a price tag of approximately $229 while the 768MB card will only cost $199 (based on reference designs). There are a couple other differences between the two cards, and the chart below illustrates those in addition to the other cards in the 400 series lineup:
As you can see above, the GTX 460 most notably has 56 Texture Units and 32 ROPs on the 1GB version (24 ROPs on the 768MB version). Further, the 768MB has a 192-bit bus while the bigger card gets the full 256-bit treatment. The clock speeds are the same, and the TDP is almost identical as well.
Let’s now move onto taking a closer look at today’s variant of this new GeForce card, the ASUS GTX 460 TOP 768MB.