Hmmmm.... I have been thinking about this question myself and I have seen a lot of contradictory opinions like the one's posted in this thread.
If you are interested in reading up about test results between 4830 CF and 4780 1 GB this is the best article I have found:
http://www.xbitlabs.com/articles/video/display/radeon-hd4830-crossfire.html
Now .... to reply which is the better of the 2, My 2 cents:
It goes like this - if you are out after the best deal there is no doubt whatsoever that the 4830 is the choice. $75 after mail in rebates will net you a 4830 as good as any other and don't even get the slightest caught up in fancy coolers, the 4830 runs much cooler than the 4780 will. I is a tremendous deal for the price - 4830 CF solution for around $150. Not only does it trounce the performance of the best $150
other options at stock - the 512MB 4870, it also smacks down the all of the $170-230
solutions involving various stock or overclocked 1GB 4870's or 216 core 260GTX's.
And thats only the starter, for the entree' you can overclock the 4830 easy from its stock 575 GPU to over 700Mhz and its memory from 900Mhz to 1000+Mhz easy peasy! Now thats something because what you have then is petty much
the same as 2 stock 4850 running CF - its gonna put hurt on the 280 GTX and shame the 285 GTX for being so dear.
And what you might ask is the bonus dessert? Well, it comes with the package too: Excellent scaling in CF configurations when playing real life games at 1680x1080 and 1920x1200, namely between 80-105% increase consistently in FPS from the single card!!! The 4870 doesn't manage this near as consistent varying between 50-85% increases in CF. Don't believe me? - Its all here in this extensive CF/SLI test:
http://www.anandtech.com/video/showdoc.aspx?i=3517 (same scaling as the 4850 because drivers are almost exactly the same)- I mean did you actually think I do any benchies? - heck no I just read stuff and regurgitate it like a seagull -
So we've come to the conclusion now that 4830 is the best GPU solution with regards to bang for the buck and has the best scaling in crossfire (similar to that of the 4850). Well, there are more questions we need to ask: Will it let you play all you new games now that you want to at the highest settings?
Another shocker: Yes! 4830 CF when OC'ed will play almost every game brand new or old can be played at max setting with the eye candy turned up so high it makes you eye's pop - just check the results out there, in fact it only falls short in a few games - Far cry 2 and crysis warhead at 2560x1600 resolution - but it flys high in the same games at 1920x1200. In fact its a bit insignificant because even the 4870 CF solution can't play those 2 games at 2560x1600 anyways. So answer for now is that you will be getting the best performance (above 30-40 FPS) on every new game at 1920x1200 resolution .. at least for now.
Then there is that other question: "Future Proofing"
- personally I think it is one of the stupidest ideas I've ever heard. How do you future proof in a industry with the highest rate of innovation and development turnover known to man!? Well the answer to that is of course you can try by wasting a lot of money - but even then you may not succeed. If you really hate me for saying this I am sorry,
but look at a previous thread comparison I made on this topic before you critique me - you might find that buying the high medium - top end is not always as future proof or financially as logical as you first thought:
http://www.tomshardware.com/forum/263121-31-gamin-build-approx-1000-time-builder
The bottom line on future proofing is this - spend only as much money as you need to play the games you like - save the rest and try to upgrade your pc once ever 1-2 years if you can be assed (otherwise just waste a bucket load and sit back for 3 years before you have to do it again
). So in the light of this revelation (well maybe its not, and it isn't my idea either - I took it from a variety of other sources who are like minded about this
) you're 4830 will probably not be as hot of an item end 2009 - beginning 2010. However truth be told, neither will the 4870 (even though some here seem to think so), mainly because DX11 is coming out, and likely so will the 5800 series. So I think the best bet is to hold out till then and see if the next generation is better instead of buying a then obsolete 4870 number 2. The $85 you save on not buying the first 4870 and the extra money you save not buying the second in a years time (who knows how much that will be) will definitely be enough to get you a next generation 5800 series - just make sure to buy the best bang for the buck of that too...
Of course I have now bigged up the 4830 CF solution to the extend that it sounds like a WWII propaganda reel
- but there are also so downsides:
1. About 50W more power draw than the 4870 single card (more if OC'ed)
2. It doesn't have the "I'm a big boy hardware know-it-all factor that the 4870 has"
3. GDDR5 memory is pretty cool
Conclusion: The sensible choice is of course the 4830 CF, although waiting till the 4770 comes out might not be a bad idea before you buy.
-However if you like the 4870, its raw power, cooler looking GPU cards and the idea of the bragging rights it will give you - get it, you probably won't be disappointed either because its a good card and you'll probably never remember all the money you could have saved.
Its kind of like buying an Audi R8 instead of a Nissan GTR, the Audi is actually not as fast but my oh my does it look cool! And somehow 2 of them together are faster than one in both cases
-
On that bombshell I wish you the best of luck with you're purchase and future gaming - good night.