I currently have a Diamond HD 4890 with factory OC and I have been very happy with it. I know someone
that has a Sapphire HD 4890 Vapor-X 1GB OC for sale for $120. If I X-fire these cards do you think I will
get a decent performance upgrade for the money? I dont have the funds right now to pay 300+ for a new card.
The only drawback I can think of is that these cards don't support DirectX 11.

Thanks for the help!

Here is some food for thought. 3d mark findings.

http://www.tomshardware.com/charts/gamin...od%5B3260%5D=on

Looks to me that it would be a good move.

The HD4890 is much like my HD5830s speed wise.

The crossfired HD5830s played everything at highest settings at 5760x1200 Eyefinity (except FSX, have to turn settings down when using all my 3d party addons).

While I have a DX11 game, the ones I like are not DX11 -- yet.

The next big thing in GPUs will come in late Fall (?) -- the 28nm GPUs from AMD and Nvidia. Good to save money for those.

Crossfire was a fun experiment. I even overdid it and got two HD5870s to try. They were not enough faster to "see" a difference (though I could measure a difference). So, I surmise two HD4890 would be plenty fast for practical purposes.

My conclusion, Crossfire does not help every game (some are CPU dependent, others run perfectly well on only one card). Nonetheless, its a fun/educational experiment if one can get the extra card cheap.

Maybe I'm biased and thus my perception is wrong, but I keep seeing threads about new games where Crossfire or SLI Support is not working, not properly working, or even making the game unstable.

If this has improved in the last year or two I honestly can't say. For 120 Bucks it certainly would be a nice performance benefit, if your PSU and Cooling can handle the additional demands.

Which games are you playing actually? My single 4890 still seems to crush pretty much everything thrown at it, including newer titles like Just Cause 2, F1 2010 and such.

I agree with you RS, so far my 4890 has handled everything I can throw at it without having to sacrifice much in the way of detail. I
plan on buying the DCS A-10 sim at the end of the month and judging from the detail I see in the screenies I'm not sure the old 4890 will be up for it. Maybe it will, it hasn't let me down yet.
I have decided to hold off for awhile and just get a better single card later down the road. I would like to avoid X-fire issues that seem happen (ie. heat,power,drivers etc.)

Thanks for talking some sense into me!!

I have two XFX HD5850s in crossfire, and honestly I can see very little difference in actual game performance. There is a huge difference in benchmarks but my eye cannot see the difference between 45fps and 120fps. I put them in crossfire because I took my simpit apart and thought I might as well use the extra HD5850 while it is sitting around.

If you are happy with game performance now I doubt you will see enough difference to justify the cost (my opinion, yours may vary).

Allen brought up a very good point though, with newer and better video cards coming out in a years time you might wait and grab one of them when your card truly does seem to be showing its age. Or, you can wait a bit and find an HD4890 for even less as they get further and further outdated.

There are several used HD5870 cards available for around 200-220 (shipped) and HD5850 cards for around 150.00 so you could also aim higher and sell your current card to help defray the cost. (Prices quoted are from the for sale section on Overclock.net where I have purchased and sold many PC components over the years.)

Hope this helps

David

Thanks Propnut! That basically cements my decision.

Not strictly comparable, but I run Rise of Flight, which is about the same generation of moderm flightsim GFX, also very detailed cockpits, shadows inside cockpit, nice ground terrain, and it runs at 50FPS with everything maxed at 1920x1200.

Depending how A-10C is optimized (LOMAC was a system hog) I would not expect it to be that much worse, so playable 30FPS at least should be possible on our cards.

I certainly plan to avoid SLI/Crossfire in the future and always go for the fattest single GPU I can afford. It saves a ton of headache judging by what people have gone trough to get decent dual GPU performance and stabelity in some less than optimal sims.

Crossfire has caused fewer problems than I imagined.

One game didn't load with Crossfire enabled -- so, I disabled Crossfire for that game (an older game so FPS was very fast without Crossfire). A couple other older games played no faster than with a single card -- but, FPS were high with one card. Occasionally, I get an on-screen momentary glitch that might be Crossfire (not sure). My newer games don't seem to have issues.

Eyefinity is the same way -- doesn't always work with every game. However, it works with nearly every game and is well worth it.

Mostly, just leave Crossfire (and Eyefinity) enabled all the time for normal "business" use and games -- its transparent (except as noted above).

Crossfire makes sense for Eyefinity -- and when one already owns a good Crossfire capable card and can get the second one cheaply (which happens when the next generation cards are released). Still, if the FPS is 25+ prior to Crossfire, one won't "see" the difference. A faster GPU or CPU, Crossfire or SLI only makes a worthwhile "visible" change in a very narrow window -- when initial FPS is between 10 and 20 and FPS is GPU limited (or CPU limited if one is changing CPUs) -- not many situations like that.

Well said Allen. All of my games work whether crossfire is enabled or not, even if they do not make use of it (Rise of Flight, Falcon AF) and the only reason I do see a difference in some games (BBC2) is the Eyefinity resolution that I am using (3150x1680). With a single screen and 30+ fps, you are good to go for a while.