FSX and Crossfire

[Guest Surfstud31]

I read somewhere here in the forums that FSX does not work with Nvidia SLI. Is the same true for FSX and ATI Crossfire? If this is true then there is no point to having dual video cards for FSX?I'm looking to upgrade in the upcoming months and dual ATI cards with Crossfire was one of my options but if it doesn't work for FSX, then there's no point for me to do it.

[Illegitimi non carborundum 4]

SurstudYou are better off with a single gpu and nVidia seems to have better performance in FSX. This is the definitive answer: http://www.steve-lacey.com/blogarchives/20...imulato_6.shtml.But having said that some simmers have had success with SLI cards, but as I only use FSX/FS( a single GPU eg GeForce 275/285 is what I would go for.RegardsPeterH

[Guest Surfstud31]

Thanks Peter, that was an interesting link. I'm afraid I am a die hard ATI guy. I would use Nvidia for any other game but for some reason with MS FlightSim, I have always had problems with Nvidia. I did have an issue with ATI during their 2xxxx series of cards. IMHO, those were not very good cards and I had major problems with the drivers. When I bought my Radeon 3870, however, all problems disappeared and my graphics have been quite good ever since.Actually, I can run FSX fine right now with the system I have (see signature below). Where I run into problems sometimes is online at my flight club. Once you get FSX running, then FS Inn, TeamSpeak, ASX, etc., it begins to bog down my system. So, by the end of the year I was hoping to upgrade to a new FSX gaming computer. I just wasn't sure if CrossfireX would work in FSX and therefore was it worth it.I checked the CrossfireX forums and one guy said for certain thet CrossfiireX DOES work in FSX and he even sees the logo to prove it: "Mine works fine with FSX and cat 8.11 although the first time i cranked it up, the logo wasn't in the corner.... I enabled logo using right click on ati logo in bottom right hand corner then click on display adapter and select the option. Then had to shut down and restart - the logo was then displayed when running FSX. I don't think it's a case of crossfire not working - if it's not enabled you will see two display adapters for each card. while correct operation will only show 1 for each. Manually switch off crossfire and you'll see the difference."So that obviously answers my question and may perhaps help others who wondered the same thing. Running dual ATI cards with CrossfireX apparently does work with FSX.

[Gizmo 0]

ATI have a major problem with clouds in FSX (this seems to effects all there 2xx 3xx & 4xx chipsets) basically any type of heavy or overcast weather with massies of cloud will drag your framerate into the teens which is why using ASX bogs down your system and dispite this problem being reported to them time and time again both in there own AMD.game forums (just check the sim section for loads of FSX threads) and via there cat crew feedback page they yet to do anything about fixing it......one of there beta testers says it because FSX is an old cpu limited game so there not going to do anything about fixing it dispite it being its market leader,myself i think its because its missing one important ingrediant and Benchmark Modenot only do ATI have cloud rendering issues they also lag behind Nv by about -%33 like for like setting on the same core system/hardware infact Nv's last gen cards are faster in FSX than ATI current gen cards! http://www.tomshardware.co.uk/radeon-hd-48...w-31433-22.htmlAlso Crossfire might get you a higher AA mode but wont give you any more performance (see above link for info)LatersGizmo

[gman! 1]

I have a HD 3800 series card too. The only difference between the 3850 and the 3870 is:* The 3870 has 512MB of memory and the 3850 has 512MB memory most of the time.* The 3850 has GDDR3 while the 3870 has GDDR4.The GPU is exactly the same, and the design references are similar, with only some voltages being different.I have a special 3850 with 512MB though, and I Oced the core past the 3870 stock, and I overclocked the memory to about 2.06 GHz effective.Crossfire doesn't work with FSX as SLi doesn't work with FSX. FSX just isn't programming to take advantage of either. In the days of development, probably 2004-2006, Dual GPUs were not very big, and same with CPUs, they were just getting into dual-core. I think if your system gets bogged down overclock the CPU, because when I had a AMD X2 4200+ I oced it to about 2.8 GHz. Or if you don't want to do that, I recommend getting a Phenom or a Phenom II to help your system because you will have 4 cores, and you can assign ASX, antivirus, Teamspeak, etc, to the last 1 or 2 cores, using the affinity mask in the task manager.With the latest driver from ATi, I get perfect frames in the clouds. With a default C172 and overcast on the ground and in the clouds, the FPS is still at about 35.BTW, the only difference between the HD 29** series and the HD 38** series is a dieshrink, new memory, a 256-bit memory bus, UVD, Powerplay, and DX10.1, but they do perform better than the 29** series. :(Make sure you have an AM2 or AM2+ motherboard that supports Phenoms before you get one, and also download the latest BIOS. If not and you still want to upgrade, I would say get an AM2+ motherboard. They support Phenom I & IIs both AM2 and AM3. The motherboard I have in my sig (the Biostar) is about 99 bucks, but is probably cheaper now, compared to other more expensive boards by the competitor (I won't mention their name) which start at $179!! :(.

[Guest Surfstud31]

Thanks for the tips guys! Yeah, I already have my GPU overclocked a bit on the ATI 3870. My system handles clouds just fine. It is only when I am online using FS Inn, TeamSpeak, etc and many other players are around that once in a while it will bog down. But everyone I know complains about this whether they have ATI or Nvidia.I was looking at Vigor Gaming Computers and they have some nice package systems with AM2 or AM2+ motherboards and lots of options for ATI graphic cards. If I don't build one myself, that may be the direction I will go. Anyone familiar with Vigor Gaming Computers? Are they a pretty good company?

[Illegitimi non carborundum 4]

SurfsudCouldn't answer before due to forum being inavailable. I learned a lot from the posts here and as you say SLI seems to be a positive for FSX. But from all of the reports/figures that I have seen is that a SINGLE GPU runs FSX "better" than a dual eg SLI/CF. I'm also looking at a Phenom II X3/X4 upgrade to my system as I think that will give me a decent FSX rig, with a single nVidia card.RegardsPeterH

[Clipper Ocean Spray 189]

Also, you can easily turn crossfire "on" or "off" via a selection in the ATI CCC user interface, which is useful if you plan to crossfire unequal cards. E.g., I crossfire a new 4890 1GB w/ an old 4870 512MB. In crossfire mode, that functions as two 4870(s) cards with a combind 512MB memory, which performs much better than a single 4890 at 1920x1080 (in my experience) for a crossfire application. For FS9/FSX however, which doesn't gain from crossfire, I turn it off to obtain the benefits of the stronger 4890 1GB card.

[Guest Surfstud31]

But from all of the reports/figures that I have seen is that a SINGLE GPU runs FSX "better" than a dual eg SLI/CF. PeterH

Peter - I had heard the same thing. It concerns me because yet another option is the 4890 X2 but that has 2 GPU's on one card. Clipper, I'm assuming your 4890 is not an X2? That means a single GPU 4890 1 GB would be a pretty good choice? (Or the equivalent Nvidia single GPU card). Is the NVIDIA GeForce 9800 GT a good card? I'm curious because I saw a deal for an AMD Phenom quad core 3.0 ghz with a 9800 GT graphics card.

[Illegitimi non carborundum 4]

Surfstud(Sorry I missed the "t"). A single GPU card with 1 GB would be a reasonable choice if your mobo/cpu/OS is up to it. I don't think that FSX will address anywhere near the 1GB GPU RAM, so it may be overkill. I haven't seen any reports that FSX runs "better" with 1GB RAM over 512 MB. Also on 32-bit WinXP systems there may be an issue with the Virtual address space resulting in OOM's. Yet again there are quite a few posts in the forums where simmers are using 1 GB cards with no adverse issues. Let's hope the new sim postulated by Aerosoft overcomes these graphics "problems".RegardsPeterH

[Clipper Ocean Spray 189]

Clipper, I'm assuming your 4890 is not an X2? That means a single GPU 4890 1 GB would be a pretty good choice? (Or the equivalent Nvidia single GPU card). Is the NVIDIA GeForce 9800 GT a good card? I'm curious because I saw a deal for an AMD Phenom quad core 3.0 ghz with a 9800 GT graphics card.

Yes, there are no 4890 X2(s) yet. I'm glad you raised the X2 issue. An X2 card provides a better crossfire arrangement than two separate cards, but you can't turn crossfire "off." My 4890 runs FS9/FSX well, but the conventional opinion here would probably be, if you're mostly planning to use FS9/FSX and you're on a budget, upgrade your computer with a GTX 285 and an i7 920 D0 (cpu, mb, and memory). A fast phenom II coupled with an AM3 board (DDR3) would also be good.