Still puzzled

K

KellyB

Charter Member
Over on FSX forum, I posted a query for video card advice and got lots of good help, as usual. Ordered up a nice new gtx 650 with 2gb of gddr5 which is on its way. the rest of the rig, including an i5-3750 is already here.

The puzzle I have is that I tried gpu-z with identical flights in FS9 and FSX, the Cessna 172 at Seattle.

In FS9, gpu-z showed a 100% gpu load, while FSX showed about 35 to 49% of gpu load.

Now, I would have expected it to be the other way around.

Any comments?
 
I could be wrong but I think that may have to do with the different architecture of the two Sims regarding the use of the CPU(s). FS9 being the older one simply runs on one CPU only.
FSX can if set up correctly run on multiple cores therefor lightening the load on the individual ones.
Plus there are bound to be some general changes in how the newer simulator does things regarding processing power in general since the boys and girls in Seattle learned new things along the way.
In other queries along the same lines I have read "software experts" opinions on the general coding of FS which was at times rather harsh. Maybe that code got more efficient in the new sim and taxes the system less.

Cheers
Stefan
 
Very helpful post Navtech.
And no I am not at all confused if you bother to read my post and think about my theory you may see the point I was trying to make. I do however not claim that this is for certain what is going on .... It is a theory based on other things I have read over many years of involvement with FS.

If you have a better one I am all ears, or eyes as it were.

Stefan
 
Sunny9850 said:
I could be wrong but I think that may have to do with the different architecture of the two Sims regarding the use of the CPU(s). FS9 being the older one simply runs on one CPU only.
FSX can if set up correctly run on multiple cores therefor lightening the load on the individual ones.
Plus there are bound to be some general changes in how the newer simulator does things regarding processing power in general since the boys and girls in Seattle learned new things along the way.
In other queries along the same lines I have read "software experts" opinions on the general coding of FS which was at times rather harsh. Maybe that code got more efficient in the new sim and taxes the system less.

Cheers
Stefan
Click to expand...

Hi Stefan:
I get the loads on the cpu's and how FS9 will only see one core. But how does that impact the load on the video card? Does FS9 shift the load to the video card whereas FSX uses the cpu?

I'm hopeful my new i5 based rig will just take care of some of these questions, and that a full 4gbs of ram and 2gbs of video ram will speed the sims up over my duocore 2.13 and 1gb of video ram.
 
That shouldn't happen...FSX does much more stuff in GPU space than FS9.

Could that be a NVidia technology trick (CUDA?) for doing otherwise CPU internal calculations in the GPU at work?
But that would mean that CUDA actively fetches stuff to do from the CPU...but from what I can read on Wikipedia, this can't be the case as using CUDA requires specific instruction sets which definately weren't there when FS9 was released.


It's a mystery...
 
Bjoern said:
That shouldn't happen...FSX does much more stuff in GPU space than FS9.

Could that be a NVidia technology trick (CUDA?) for doing otherwise CPU internal calculations in the GPU at work?
But that would mean that CUDA actively fetches stuff to do from the CPU...but from what I can read on Wikipedia, this can't be the case as using CUDA requires specific instruction sets which definately weren't there when FS9 was released.

It's a mystery...
Click to expand...

I forgot to mention that the video card is an ATI 4680, so Nvidia isn't involved.
 
KellyB said:
Hi Stefan:
I get the loads on the cpu's and how FS9 will only see one core. But how does that impact the load on the video card? Does FS9 shift the load to the video card whereas FSX uses the cpu?

I'm hopeful my new i5 based rig will just take care of some of these questions, and that a full 4gbs of ram and 2gbs of video ram will speed the sims up over my duocore 2.13 and 1gb of video ram.
Click to expand...

That is exactly the point I was making. How exactly this works is above my pay grade. If indeed this is how FSX got a little less GPU intense and shifted more work to the CPU. Again this is what I gathered from reading similar discussions on other FS related forum pages.
The problem with the Internet is that everyone can claim to be anything.

I think that with modern hardware you will have no trouble running either version of FS, since now the hardware has caught up with MS.

Stefan
 
Perhaps MicroSoft's intention with FSX was to shift more load to the CPU, thus making the sim playable on a wider variety of video cards? My aging Nividia 8800GT seems to have little problem with FSX, it's the CPU and RAM that works the hardest.
 
stansdds said:
Perhaps MicroSoft's intention with FSX was to shift more load to the CPU, thus making the sim playable on a wider variety of video cards? My aging Nividia 8800GT seems to have little problem with FSX, it's the CPU and RAM that works the hardest.
Click to expand...
Same here. I run an aging Dual Core system with an NVidia 9600GT and only 512meg of ram and most of my sliders are far right, but the 3.0ghz CPU is what helps immensely. :salute:
 
Thanks one and all for the insights.
As Stefan observed, the reasons for FS9 and FSX's behaviors is also above my pay grade.

Merry Christmas to all, and I'll report the results of the new build when the remaining pieces (starting with the case) get here.
 
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