The only people that know for sure are nVidia. It seems to me that GF114 is just GF104 with all the shaders enabled, they even have identical transistor count(while the transistor count changed between GF100 and GF110). Even the power consumption went up with the extra shaders/clock speed(while it went down between GF100 and GF110). To me that shows that there really is no difference between GF114 and GF104, or if there is any difference it is extremely minor. The slightly better overall overclocking of the GTX560 could entirely come down to the 4+1 Power design of the GTX560 vs. the 3+1 design of the GTX460.
Here are few quotes from Anandtech's technical review that may shed some light:
GTX 560 Ti, in a nutshell, is a complete video card using the GF104 design; it is to GTX 460 what GTX 580 was to GTX 480. With the GTX 460 we saw NVIDIA disable some functional units and limit the clockspeeds, but for GTX 560 Ti they’re going all out. Every functional unit is enabled, and clockspeeds are much higher, with a core clock of 822MHz being what we believe is much closer to the original design specifications of GF104. Even though GF114 is identical to GF104 in architecture and the number of functional units, as we’re going to see the resulting video cards are quite different – GTX 560 Ti is quite a bit faster than GTX 460 most of the time.
So how is NVIDIA accomplishing this? Much like what GF110 did for GF100, GF114 is doing for GF104. NVIDIA has resorted to tinkering with the Fermi family at a low level to optimize their designs against TSMC’s mature 40nm process, paying much closer attention to the types of transistors used in order to minimize leakage. As a result of the more mature manufacturing process and NVIDIA’s optimizations, they are now able to enable previously disabled functional units and raise clock speeds while keeping these revised GPUs in the same power envelopes as their first-generation predecessors. This is allowing NVIDIA to improve performance and/or power consumption even though these revised chips are virtually identical to their predecessors.
On GF110, we saw NVIDIA choose to take moderate gains in both performance and power consumption. In the case of GF114/GTX 560 however, NVIDIA is choosing to focus on improving performance while leaving power consumption largely unchanged – GTX 460 after all was a well-balanced part in the first place, so why change what already works?
In order to achieve the larger performance jump they’re shooting for, NVIDIA is tackling this from two sides. First of course is the enabling of previously disabled functional units – GTX 460 1GB had all 32 of its ROPs and associated hardware enabled, but only 7 of its 8 SMs enabled, leaving its geometry/shading/texturing power slightly crippled from what the GF104 chip was fully capable of. Like GF110/GTX 580, GF114/GTX 560 Ti will be a fully enabled part: all 384 CUDA Cores, 64 texture units, 8 Polymorph Engines, 32 ROPs, 512KB L2 cache, 4x64bit memory controllers are present, accounted for, and functional. Thus compared to GTX 460 1GB in particular, GTX 560 Ti immediately has more shading, texturing, and geometry performance than its predecessor, with roughly a 14% advantage over a similarly clocked GTX 460 1GB.
The other aspect of improving performance is improving the clockspeed. As you may recall GTX 460 was quite the charming overclocking card, as even without GPU overvolting we could routinely get 20% or more over the stock clock speed of 675MHz; to the point where NVIDIA tried to make an unofficial product out of partner cards with these lofty overclocks. For GTX 560 Ti NVIDIA has rolled these clocks in to the product, with GTX 560 Ti shipping at an 822MHz core clock and 1002MHz (4008MHz data rate) memory clock. This represents a 147Mhz (22%) core clock increase, and a more mild 102MHz (11%) memory clock increase over the GTX 460 1GB. Coupled with the aforementioned 14% increase in SMs, and it’s clear that there’s a quite a potential performance improvement for the GTX 560 even though we’re still technically looking at the same GPU.
As NVIDIA is not looking to significantly move the power envelope on the GTX 560 Ti compared to the GTX 460 1GB, the TDP remains similar. NVIDIA never specifies an idle TDP, but with their transistor level changes it should be lower. Meanwhile load TDP is going up by 10W, from 160W on the GTX 460 1GB to 170W on the GTX 560 Ti. 10W shouldn’t make for a significant difference, but it does drive home the point that NVIDIA is focusing more on performance at the slight expense of power this time around. GF114 is pin compatible with GF104, so partners can drop it in to existing GTX 460 designs, but those designs will need to be able to handle the extra power draw and heat. NVIDIA’s own reference design has been bulked up some, as we’ll see when we dissect the card.
So while pin compatible with the 460 GF104, the internals are different.
...Holy Shit...THIS CHANGES EVERYTHING!!!
