Prepar3D Forums

Hello,



I just upgraded my video card from an AMD 6750 to the AMD 7970. My issue is, although my benchmark software has shown a significant performance boost in all areas, I am not seeing any additional performance within P3D 1.4 using identical rendering prefs and monitor setup. What am I missing?



Graphics Card

Radeon HD7970-DC2-3GD5



Operating System

Win 7 64-bit; Service Pack 1 build 7601



Issue Details

Poor performance (framerate) in Prepar3D 1.4 64 bit



Motherboard or System Make & Model

Gateway FX6860, Intel Core i7-2600 CPU @ 3.4GHz, 3401 Mhz 4 cores, 8 Logical Processors



Power Supply

FSP Group FSP450-60EP, Max wattage 450 Peak 500, full specs http://www.fsp-group.com/english/1_product/2_detail.asp?mainid=1&fid=176&proid=656



Display Device(s) and Connection(s) Used

3 Samsung 23” HD S23B550 1680 x 1050 @60Hz extended via HDMI, Display Port, and DVI



Applications and Games

Prepar3D 1.4 64bit



CPU Details

Intel Core i7-2600 CPU @ 3.4GHz, 3401 Mhz, 4 cores, 8 Logical Processors



Motherboard BIOS Version

American Megatrends Inc. P01-A3, 4/19/2011



System Memory Type & Amount

UNIFOSA 2GB DDR3 1333MHZ UNB. DIMM

The answer to that question is quite simple.



From my experience there are at least three main considerations to keep in mind.



First, flight simulators are not GPU intensive applications unless you are running quite a few monitors off the one graphics card



Second, ATI Radeon + Flight simulators = fail!!!



Unfortunately, i am still of the opinion that Ati cards simply do not produce the same quality of simulator display experience. I have two cards...a gtx 570 and an Ati 6970. Now one would expect the 2 gig Ati Card to have it all over the gtx 570 (1280Mbgyte) however, this is simply not the case. The Nvidia card is by far the better GPU running prepar3d!



Now i know that prepar3d is supposedly aligned with AMD as a partner, however i dont necessarily believe this makes any difference between Ati and Nvidia.



Third, whilst it may or may not affect your current performance, that 450 Watt power supply is a little on the small side for high end machines, particularly since you have upgraded the video card to a 7970 (according to AMD's specs sheet, the GPU alone is rated at 300 Watts!!!). i am of course making the assumption that it only achieves that level when in eyefinity mode... however, you said you are running 3 monitors. I run a minimum 750 Watt PSU on my system with the Ati 6970 card and multiple monitors and i have just upgraded to a 1000 Watt one. By the way, just because your PSU says it is 450 Watts, you need to check the actual continuous rating is actually 450 Watts (many cheapo ones are not continuous at the specified wattage). Also, what amperages are being supplied to the individual rails. You may not have enough amperage on the rail supplying power to the GPU!

Thanks so much for your reply and insights adamjedgar. I do appreciate it. However in the time since I posted, I remedied my performance problems with a full uninstall of the ATI drivers using ATIMAN and re installation from the Video Card installation disk. Running three 23" Monitors in Eyefinity mode, I was able to fly the PMDG NGX around Seattle with Clouds and ORBX PNA and full renderings at 40fps. Looks like the old driver files were hanging around and not playing well with others.



Cheers,

Michael