How do all of these compare?

I play at 1680x1050. Will the bottleneck in most games be fairly small?

Two 4890's would be about $300. Would this be a better option than the 5870 despite power usage the lack of Direct X 11? Will the benefit of crossfire diminish in some games or is it constantly better than the 5870? Will my 700W FSB PSU have any problem running two 4890's?

i agree.

mine is pentium e5300 and i got 80+ in gta4 with 9800gt in mid-high setting(4aa, 8af 1024x768)

amd's just not as good

BS! An e8400 cant even get 46 and you are telling me a much weaker one can get 80?
http://www.tomshardware.com/charts/2009-desktop-cpu-cha...
i think not, a 9800GT would crash headlong into a CPU bottleneck at that resolution, and a pretty big bottleneck at that.

At 1680x1050 a single 4890 should be plenty, however it will be bottlenecked by the CPU in most cases, crossfire tends to just make CPU bottlenecking worse, though if you drop an athlon II 620 in there it should help GTA immensly. Depending on your 700 watt PSU it may be alright for crossfire, but its hard to tell without knowing the exact model, link to it if you could.

you are comparing athlon 2 250 to a e8400? a 8400 would destroy any amd dual core by a long shot. a 8400 cant get 46? what resolution you play? driver issue? directx bug? virus? you simply cant provide any more info about how'd you get 46fps when play gta? or you are just had a athlon had 46fps and pretend it had same performance as e8400?

i have 4gb ddr2 800 dual channel with e5300 + gigabyte 9800gt and i even use fraps in the game and i got 70-80s in benchmark under 1024x768 with 4aa. i wonder what amd processor would do in it.....30? or may below 10

in other word you had no evidence that wtf you're talking about

Look at the link, its not me who cant get 46 FPS, its the benchmarked system here, dont accuse someone of not having evidence when you just quoted a post with a link to the benchmark tables here that show exactly what i just said. Take a look at the link.

then why am i get the score that is much higher than the benchs on fraps? is that my probelm?

but again i refuse to believe these benches because i dont believe a processor that only have 2mb cache can be so close match with a processor had vastly 6mb cache. plus in anadtech e8400 shows overkill 100fps in gta and pwn the crap out of athlons

Ok I will be short and sweet. If a 5870 is in your budget, GET IT.

You have listed options that range from a 2nd 3870 for $50 to a $400 5870. I want to first ask, what is your budget? Second, why not get the best you can now? A second 3870 won't even hit the performance of a single 4870. (2) 4870's, for the most part come in pretty close to the 5870. (2) 4890's out perform a single 5870. However, with a single 5870 you don't have to worry about potential heat issues that come with running 2 cards and it used MUCH less power, especially at idle (believe me I know). I tried to CF (2) 4870's and had alot of heat issues and ended up taking a little hit and selling on eBay to get a 5870.

Also to note about your "bottlenecking" question. Your CPU is fine, and EVERY computer EVERYWHERE is full of bottlenecks, you just try to minimize them. There are some games that LOVE fast CPU's and multiple cores. However, for the most part you won't have many issues. ATI cards are also pretty driver heavy as opposed to Nvidia cards which love fast CPU's and are lighter on the drivers.

My power supply has four rails with about 15 amps each, but I'm not positive on that.

My budget is not the determining factor here. I have the money to get any of the options, but I'm not positive that I want to throw down $400 on graphics card today. A second 3870 might extend my PC's life until prices come down. If I bought one 4870/4890 today, I could wait a while to get the second one. Also, you say that 2 4870/4890's will beat a 5870. I may only need one 4870/4890, since it is still a very powerful GPU. There are so many options that I'm not sure which way to lean. I'm willing to spend $150-$300, but I want to get what I pay for.

I know a 5850 would be more efficient and cooler, but I could get 2 4890's for the same price with significantly better performance. Plus, I could buy one now to hold me over until they get cheaper. This would give me a significant performance increase without springing $400.

I also hadn't thought about it, but how do 2 gtx260's compare?

You have an older dual core, which will limit how much you can extract from your graphics solution. Single card set ups would probably be your best bet for any sort of return on investment.

At 1650x1080, a 4870 512mb would be more powerful than adding a second 3870, won't be succeptible to CF support issues, and is not very expensive (about $130). You would get a huge performance increase, save some cash towards a 5870 price drop situation. Or you could invest a little more for a 5770, get similar performance with DX11 access to boot. They also scale at nearly 100% in crossfire, further adding to upgrade value in the future, should you upgrade your CPU to take advantage of that sort of horsepower. I am looking at a new build in January, and am pretty much set on going with a 2x or 3x 5770 set up just for that reason.

I wouldn't recommend an Nvidia card (or 2) atm. They are way overpriced compared to their ATI counterparts, and none have the option of supporting DX11 yet. You will get a much better performance return on an ATI setup right now. If you are dead set on Nvidia, a single 260 would probably be all you could utilize, or drop down to sli 250/9800gtx, but from your consideration of Nvidia as an afterthought, I doubt you are too dedicated to one brand or another, heh.

At $150-$300 I'd shoot for a 5850, if you can find one. A single card is always easier and less issues. If not a 5850 I'd shoot for a 4890.