My computer is worth about $700 and I have an Athalon 2 x4 840 Propus (mislabeled as Phenom). It is not like a 2500k by any stretch, but it is cheap and it holds its own in speed tests.
I think I got it for about $80, which is why I don't really expect it to keep up with a $210 2500k. It did, however, save the other $130 for other parts.
Anything 955+ is also good, though, if you can get it cheap enough. Just stay well below $200 if you are going to get one because otherwise you should just take the 2500k instead. The 2400 processor is also just a tad under $200 and outperforms similar priced AMD chips.
Anything you can get in the 955+ range with a cost of 120 - 150 is OK except don't get the FX processors (unless you can get an 8150 for that cost). A 960T Zosma might be nice if you have a motherboard with UCC capable of unlocking disabled cores. I would definitely try to stick with something that is x4 or better, though.
you can put most any two processors head to head in about 40 benchmarks.
Pick the benchmark that is closest to what you think you will be doing commonly and compare a few processors in your price range.
In the i3 2100 series vs 1090T battle, the 2100 barely beats the 1090T on some things and gets absolutely killed by the 1090T in others (music encoding, h.264 encoding, 3dsmax, cinebench, pov-ray, 7zip). The i3 does, however, require much less power than the 1090T which is noteworthy.
I'M running a 1090T in my system that has a Gigabyte motherboard (GA 870a-USB3), and 16 GB Gskill memory. Also with radeon graphic. So, that system is almost identical to yours.
Now, is it fast? yes. Is it stable? rock stable. Is it smoth running? yes. To be honest, every CPU above 2.8 GHz is fast enough for non high end gaming and the more core you have, the smoothest the ride. I have cool and quiet enabled and most of the time, it is running at low MHz (800-1600 MHz) unless I'm doing some kind on encoding or rendering or any CPU intensive apps. which is not very often.
oh.. depending of the video card, you'd better get a more powerful PSU. I had a 500W in mine and It started to whine when the systen was loaded. a 600W fixed it.
I'm pretty sure you'll be happy with it and it can even overclock nicely. I did not overclock mine thou. Plenty enough for now.
With application now starting to use graphic card for some rendering, that will help to unload the CPU of demanding task.
You seem like a person that knows a lot about builds. Can I get you to look at my current build and rate it?
Considering gaming isn't an issue with you and photo editing is, the 6 core processor will be a better choice than any 2 or 4 core processor. The build looks like a good one for your stated purpose without going overboard in cost. Use the link Raiddinn sent to model the processors side by side. But I think your selection is solid for your purpose.
I would recommend going with a bit larger PSU, though, for future proofing. (In case you want to upgrade to a mid range gaming card later) Use this PSU calculator to get an idea of what you will need. Bigger won't hurt a thing other than your wallet. http://www.thermaltake.outervision.com/
The video encoding the OP wants to do is the justification for the x6 1090T. An AMD x4 or hyperthreaded Intel i3 are not on the table for this task. I think it would be worth comparing the faster-per-core core Intel i5 CPUs for it, but this may be that very rare case where the AMD x6 makes sense. Look for specific benchmarks of the program(s) you will be using, if available. You might even contact the software vendor if you're not able to find any online.
Edit: This is more or less what clutchc just said, although I'm less concerned about the PSU. If you are considering the 380W Antec Earthwatts, the only reason to look any higher is if you're certain that you will get into playing games, and will want something stronger than a HD6850; the 380W Earthwatts is very solid, and well able to output what's on its label. If you're not going to play games, and/or will get something like a HD6670 or HD6770, you'll be fine.
I would suggest the 960T but its luck if you get all 6 cores working. The one thing I can say for sure the 960T as a quad will overclock on the stock heat sink way better than Deneb quads. The larger die dissipates heat better.
If you get the 6 cores unlocked the CM hyper 212+ gets me 3.7GHz at 45c on 1.385 volts stable.
Best answer selected by Cybernetic.nnThanks for the help, jtt. I've broken down and decided that a i5-2500k would be the best for my "future-proofing." For those of you looking at this post for help, the X4 would probably be the best choice on a tight budget. If you can shell out the extra $40 bucks from a X6, the i5-2500k will perform better than the X6 and most likely the new Piledrivers set to release Q2/Q3 2012.
Thanks. I suspect when you consider power use, the i5 comes out ahead there too.
...as to Piledriver, I am cautiously optimistic; BD sucked so hard that perhaps there are some obvious and/or straightforward fixes. Come on AMD, I risked getting a 990FX, but that's the last chance you'll get from me; and I'm not holding my breath.