Jesus Altuve on the difference between ATI and Nvidia for FSX
http://forums1.avsim.net/index.php?showtopic=281538
One side note: ATI's 5870 vs nVidias GTX 285 they are both EXCELENT cards... but they have completely different architectures, the ATI's have LOTS of tiny 'slow running' shader processors, the nVidias have fewer shader processors (a lot less) but they are TWICE as fast... so, how does this affects the cards ability to 'process' and 'render' draw commands?
well.. its up to you to decide: the ATI's have 1600 small processors, they are called 'shader processors' the more processors you have, the better the card ability to 'multitask' and do parallel processing so, the ATI's are FANTASTIC reading the command buffer faster than ANY card on the planet (even the new nVidias GTX 480, also called by their codename Fermi) so with an ATI you could practically have FSX nirvana if FSX were to send all draw instructions to the command buffer bypassing the BufferPools.. however, THERE IS A CATCH. Since ATI's have more shader processors, they need to run 'slower' (they run at 700Mhz) same as the core clock. so, complex scenery, clouds, add-on aircraft will considerably LOWER your total average FPS. so, again, its up to you to decide... if you only fly default planes, and want EVERY SINGLE SLIDER MAXED out, vsync, nHancer, ENBSeries mode etc. then the ATI is for you, ITS IMPOSSIBLE TO CRASH IT! I could crash mine (I only owned it for like 2 days) no matter what I tried, but I lost 6FPS! to me thats unnaceptable.
Now.. the nVidias, particularly the GTX 285, have exactly 240 Shader processors, they run at 1476Mhz (and some can be overclocked even higher) this card, is a monster... and even though the ATI's (in raw speed) are faster, the nVidias can render 'complex' scenes much quicker (specially things that relay on shaders such as clouds, high water settings, buildings etc.), so the CPU doesn't have to wait for a particular scene to be rendered. Remember, the FASTER the card 'renders' a scene, the faster the 'frames' will be processed and the CPU will keep producing them! so, as you see, there needs to be 'BALANCE'. remember, that any complex system will be limited by the speed of the slowest running member on the system. Now, back to video card comparisons: The downside to the nVidias?? THEY SUCK at reading instructions from the command buffer fast enough, so they can be stalled by the CPU IF you are running high frame rates and using complex autogen (which is what fills the command buffer quicker, specially after SP2 where there is massive object batching per frame) so when using nVidias LIMITING your framerate to 25-30FPS and lowering autogen is paramaunt. (including the steps I have already mentioned) like vsync OFF, single monitor setup, No ENBSeries and application controlled AA and AF. but don't worry.. The GTX 480's will change all that
![Smile](images/smilies/smile.png)
they have 480 shader processors
![Smile](images/smilies/smile.png)
still much less than the ATI's but enough to give you Flightsim nirvana and turn FSX into a whole new ball game. So, IT IS completely possible to achieve what everyone though was a dream. FULL MAXED sliders and fluidity (I don't include car traffic) MAX 2.0 Water (which is a killer) or bloom (the other killer) but you can still have pretty descent AI traffic and easily achieve 20-25 FPS under the most demanding conceivable situation, thats quite good.
Bookmarks