Problem with Ati

[lordsniper]

Hello

my brother has a crossfire Ati Hd4890, but the shadows in the clouds (using R.E.X) and the shadow on the aircraft are literraly killing his FPS even with his overclocked core i7 920... it drops from 20 to 9,8 or 7 fps... I tried everything but it still doesn't change..any clue shared an experience with Ati ?
It happens only with civil heavy jetliners and with the pairbus a320 too
I have an Nvidia 9800m Gs and a p8400 and It gives better results and stability, it's shameful since he's beggining to study aviation engineering next year and he built this Pc especially for Fsx.

thanks

[iheart707]

Well, it sounds like you have a monster of a CPU, so that shouldn't be a problem... I have a couple of things that you can try to fix this issue,



1. You mentioned that you have REX installed on your PC. Take a look to make sure that your cloud texture size is NOT at 1024x1024 if you are running on a 32 bit system! This will slow it down tremendously! Try a smaller resolution like 512x512.

2. Are the 'heavy' jets true FSX models? If they are fs2004 models, this can cause a substantial loss in FPS (Frames Per Second). List some of the planes that have been giving you issues outside of Project Airbus and their fleet.

3. Have you made sure that you have adequate power going to the card? (All the connectors for power have been plugged in and double checked)

4. Sometimes Microsoft's Windows can confuse drivers for video cards. I have experienced several times problems where traces of NVIDIA were being loaded instead of the drivers for ATI and vice versa. Check to see that all the drivers and their components are uninstalled on which ever card you want to keep running all the time. *(Make sure you scan for left over registry keys)

5. Have you recently updated your graphics drivers for the ATI card? Could be a simple fix!

6. Try fine tuning settings in your ATI Catalyst Control Center™. Sometimes you might have a setting too high for your PC!



Try these, and then get back to us! Hopefully this will speed things up!

[lordsniper]

Thanks for your answers

My clouds are 4096*4096...I tried to lower the resolution but It still gives low fps, (and I use the default B747-400 for fsx to test...), but recently i discovered that the power supply (850W) was very unstable when giving a 12V rendering so I'm gonna change it, I hope it will resolve It, I tried all the drivers for 10.1 to 10.5 and I never installed an nvidia driver...

Thanks again

[iheart707]

That's interesting that you say that you got better stability and higher frame rates with a video card that had no drivers installed! :shock:

By what means did you test the power supply? Did you use a tester like this?

Or was it software based?

In the worst case scenario, you might have accidently damaged your graphics card. You might want to check it with some third party software to see if you have a bad memory chip or damaged GPU because of the 12V was uneven. It is really easy to burn out those cards if you are not careful as I’m sure you already know…

[sknepper]

I have the same problem with my ATI Radeon 4600 with 2GB of memory also with a i7 920 CPU. Somehow the clouds and even engine smoke kill my FPS to 7 or 8 fps, so I lowered the weather setting to low and never get behind the engine contrails in external view with FSX. Just installed FS2004 again to run alongside FSX. Have the same problems. Now I get just mist instead of clouds but a constant 20 FPS. Newest ATI drivers don't solve the issue either. I guess you have to make sacrifices to make gains in other departments :? .

[lordsniper]

That's a shame that I have to lower my config, but what can I do, FsX is weirdly optimised, especially for Ati...
a friend of mine tested the power supply stability and yes it sucks. For the Ati card they're fine, because they gave approximatively (because I changed the driver) the same result with 3dmark since I bought them.

the way the stability was with a kind of small portable "oscilloscope" (is it the same word in english than in french ?)

[sknepper]

the way the stability was with a kind of small portable "oscilloscope" (is it the same word in english than in french ?)

Yes, it's the same word.