Windows 7: Two 6850s or One 7850?

The title says it all. Should I get another Radeon 6850 or just replace the current one with the 7850. Also when you combine two cards, does it add the memory? Meaning if I have two 1GB cards, will it be 2GB total?

Memory won't increase, it will mirror the data so that both cards can access it. so if you have 1GB and 1GB on new card, you will still only see 1GB.

I also purchased the 6850 and it is awesome. I think 2x6850's xfired is better than the 7850:

Video Card Comparison - GPUReview.com
(in link, click "multi-gpu" to see what two cards would output)

but this is just on paper, I am not certain if it holds true in real world setup.

Also, I think the 7850 has a higher clock speed and this would be prefered. just don't get a 6870 if you do xfire as it will downclock to match the 6850 and don't get a 7xxx card unless it is the 7850 or higher. the 7770 is ok, but still not close to 2x6850 or the 7850

*also, for a laugh, check out the 7970 ghz edition on that site lol

I pretty much agree with Thorsen. He is correct on the memory also. But, I have never tried it, but would think 2 X 6850's would do better than a 7850.

The answer will depend on the monitor you have, if it is less than 27'', then the chances are that having dual video cards would would not be beneficial.

Couple of days ego, I've replaced my HD5850 with this HD7850 card, without thinking about dual mode:

Newegg.com - HIS IceQ Turbo H785QT2G2M Radeon HD 7850 2GB 256-bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card

The WEI index for the old video card was 7.7 and with the new card it is 7.9; in both case with a 24" monitor 1920x1200 resolution. The new video card is marginally better in games, and in general. On the flip side, it is runs cooler and quiter and that was the goal. Interestingly, the old card required two power connection while the new one needed only one. The newer cards are more energy efficient than the old one, dual cards would double the power consumption. Not like it matters much, even on a yearly basis, but you may need a new power supply as well with the dual cards....

Okay,

Thank you guys a lot for the replies! I have another question about the memory. Can you get another 6850 with a higher size RAM and have it add? Also, since the load is split between two cards, will it be quieter (fan speed) since it is not using as much per card?

Microstutter is also a factor, as far as I know, it is much less common in the 7000 series than in the 6000 series.
The 6850 in xfire comes close to the 7850, but if it gives you microstutter it will be a waste of money.

Lets hope AMD gets the groove on getting drivers that could reduce, or fix microstutter entirely.

Any idea whether or not I could add memory if I use another 6850? My current card is 1GB, could I get a 2GB card and have a total of 2GB? Or does the memory need to be the same size for Crossfire to work?

The memory depends on the game and resolution i was pulling somthing like 1575 GB with 2x 6870 in CF at max settings on 1680 /1050 Max payne

when using a 1920/1080 it increases to 1685 GB in use

Now that i am using 2x 7970's at max settings Max Payne will do a full 2048 GB again depends on resolution

If you are using a high def Panoramic view then it will defently increase to over 3 GB of Vram

I hope this gives you a decent Idea of the scale between cards with 1GB a piece vs a 3GB or 2GB card Variable

I would bet that IF it didn't cause problems having 2 cards with different amounts of RAM, you would be limited to the lowest amount......I'm not positive on that though.

If you are looking at the 7850, you could spend about $10-20 more and get the 7870GHz edition card. Here is a beastly card from MSI--> MSI 7870 GHz Hawk Edition. Very nice card with a $20 rebate card and a free copy of Far Cry 3.