Okay so if i have a single GeForce 295 GTX and am thinking about upgrading, it seems difficult to compare the older cards to the newer ones.
If you look at say, the gaming benchmark charts for 2011, none of the older previous year's cards are represented, and also all the benchmark programs and games are different. So how can i tell which of the newer cards is a significant improvement over my 295?
I don't want to spend a bunch of money on a setup which is only slightly better. It would be nice if the benchmarks included a few of the higher end cards from previous years, for comparison's sake.
The link below shows a graphics card heirarchy chart. It is the last page of each monthly "Best Graphics for the Money" article put out by TH. It will show you roughly what products are as powerful, set up in tiers.
As you can see, there are only 3 single cards available today more powerful than your GTX 295. Now, there are plenty of options of SLI/Crossfire configurations that are more powerful, but the bottom line is that your card is equivalent to anything less than a $500 GTX 580 or a $600 GTX 590/HD 6990.
So even if you spend a ton of money, you will only see a relatively small increase in performance. There are some features like DirectX 11 support that your card won't provide, but I am not sure if that is a solid enough reason to move on unless it's very important to you.
Edit: since the HD 5970 is not widely available these days, I did not include it as "available today" in the second paragraph.
Sadly this is not the best time for you to upgrade over such a card that you have. The GTX 295 wasn't really meant for short upgrade cycles but current gen cards are weaker than one would expect making this worse. I suggest that you just hold out for the 28nm era unless you are willing to invest in something along the lines of a gtx 580 or two gtx 570 in sli. The gtx 590 may have some appeal but at $700 I doubt that it will ever sell as well as the gtx 295 did. Fermi's shaders are also weaker than the G80/GT200 era and tend to have lower raw power to the end user overall. I will use a gtx 460 to compare with a few much older cards some that I own. The gtx 460 at reference clocks is barely 5% overall faster than a gtx280 while at the same time barely a meaningful upgrade over two 9800gt in sli. One other example is the 8800gtx vs the gtx560ti. The gtx 560ti is twice the overall performance than the 8800gtx at slightly more power consumption depending on the clocks of the g80. 139 or the 155w figure of the 8800gtx vs the 170w ref figure of the gtx 560ti but the kicker her is that the gtx 560ti has three times the shaders to achaive twice the performance of that of a single 8800gtx with slightly higher power consumption. Clocks are a major factor with both architectures. The older cards are limited in their clocks as we all know however despite this advantage of Fermi doesn't achieve the performance gains that we have all become accustomed to.
In short no there are no worthwhile upgrades on the market unless you are willing to dig deep and modern cards are weaker than expected.