Can't believe Nvidia has jumped 3 100's in the last year 0.o
Don't sweat this so much because the enumeration is mostly marketing and lots of lipstick. It helps to identify the naming scheme used for the nomenclature of nVidia's video card products:
Starting with the 200 series, most of those chips were simply reskinned 9000 series GPUs. So most 9000 series chips were the same ones used in the 200 series.
We can start with an example "GeForce GTX 460"
nVidia has GeForce and Quadro GPUs it produces. GeForce are consumer grade and marketed for end-users and OEMs. Quadro are corporate or business grade GPUs marketed for servers and mission critical workstations and are marketed as such.
The difference between all of nVidias "GXX" labels can be a bit head-scratching sometimes. As with most chip manufactures, the products are mass produced leading to some chips not performing at the intended performance of the manufacturing chip specifications. Therefore, the chips are tiered into different "GXX" labels indicating that potentially portions of the chip's features have been locked or not guaranteed compared to the "top model". In general....
GTX > GTS > GT > GS
In our example, our GTX 460 is the "top" model of the 460 dye process and technology of the GPU.
Realize some GPUs were only produced with one or more of the above "G" labels. Some of these were relabeled at the next numerical model label:
"XYY" is the current numeric formula for the model number of the GPU. The "X" refers to the generation of chip signified by potentially a new dye process, new chip features, new technologies, etc. The "YY" refers to number assigned to the tiered maximum performance of the chip. So using our example the GTX 460:
generation ---> 4 60 <------ performance tier
The perforance tiers are labeled from highest to lowest as such:
95
90
85
80
75
down to
15
10
Each increment of 10 generally signifies a jump in the amount of technology performance of the chip. This means you will see larger memory bus sizes, memory size, and even different memory standards (DDR3 vs. DDR5 for example). Each increment of 5 generally denotes a difference in speed of the compenents -- GPU core, shaders and memory will have their default and tested speeds increased. To use a crude analogy, each 10 increment increases the number of cylinders in a combustion engine. Each increment of 5 increases the size of the intake valve.
In summary, I realize that your 295s probably seem to pale in contrast to the new 500 series models, but you pretty much have the BMW of the 200 series chips -- and in SLI! Realize that your two 295 GTXs SLI almost beat on average the performance of single GTX 480 cards and compete pretty well with GTX 460s in SLI. Don't believe me?
Admittedly we are just talking performance here. Of course upgrading will get you DX11 peformance and all the new and upgraded technologies as well as many other goodies the new generations of chips offer. The graphics will look better and feel richer on new 500 series vs. your 295s. But speaking in raw performance numbers, you still have a beast setup with 295s in SLI which is on par if not beating the performance of most of the 300 and 400 series GeForce chips.
