...... a video card with more memory would most likely give you the best results for the money.
Nope, not that either, the video memory is adequate unless you have some massive display at a very high resolution. It's the GPU that is the determining factor. If you want 30-40 FPS at full driver settings, sliders maxed in heavy scenery, you'll need a 7900GS -> 8600GTS overclocked to buggery, or 8800 series.
BTW, the 7600 you have will get close if it's wound up and the system is tweaked out.
Basically, there's a few options in hardware, but you don't have to spend a thing imho, you already have the equipment to get you close to nirvana. You just need to give her a boost and get your system/OS/software configured properly.
BTW, a new fast HDD will help slightly, particularly if your current drives are more than half full.
The thing is, it's all fine now for FS9, but you could spend more on this good, but aging machine, I know, I'm running two similar systems. Is it worth it or will you consider an upgrade within 12 months?
It maybe best to tweak what you have and get into something better next year if you need to. By then, you'll see spares for the current rig going cheap on ebay anyway, (possibly now).
Now, from a hardware view, and if you want to spend money on this rig to max it out, you need a socket 939 3700+, 4400+ or 4800+ (there are also some opterons that are suitable) with a view to overclocking it with some quality overclocking ram, see my spec below.
The only benefit a 3700+ will have over your 3500+ is it's extra clockspeed in the overclock (maybe) and it's larger L2 cache. A dual core will alleviate some processes on the gaming core but probably won't clock as high, much of a muchness unless you are sloppy and run a lot of background tasks and multitask a lot, where the dual core may be better.
An 8800GTS will get you enough FPS, no bottleneck with that card on this rig. The 7900GS and 8600GTS alternatives will need to be overclocked to 8800GTS levels to do the same job, and for that, you'll need exceptional cards.
The HDD makes such a small contribution to overall sim speed, it's hardly worth considering, BUT, if those drives are currently slow or full, you MAY notice the difference with a fast new drive, particularly if you can fit everything onto the first half of it.
To get the overclock happening, start a thread in the overclock forum and I'll try to help. I've spent a couple hours with that bios some time ago.
To get the system tweaked, see NickN's gospel here for starters:
http://www.simviation.com/cgi-bin/yabb2 ... 53;start=0What exact AN8 is your board? Ultra? SLI? 32x? Fatality? or just plain vanilla? Revision no.?
You are showing 1.5gb of ram, this is a definite bottleneck unless you are currently running 1x512+1x256 + 1x512+1x256 PC3200 or above in dual channel mode, even then, I think that could be a slight bottleneck. You want 2x1024mb modules in dual channel configuration, either super fast low latency PC3200 or PC4000 or above.
The AN8 will do wonders for that 3500+, though the 3700+ San Diego is a better cpu. (the 3700+ Sandy is still available new)
Some ground can be gained also with a 4400+ or 4800+ fitted, but you will probably have to source a second hand X2 unless you go for a new opteron if you can find one..
2gb of PC4000 will get you a good overclock at 1:1 memory ratio for that 3500+ or better cpu. PC4000 runs at 250mhz (DDR500) and allows the cpu to run at 2.75ghz with an 11x multiplier and ram at 250mhz with the FSB set to 250mhz... ie. 1:1 ratio.
If the 3500+ won't do 2.75ghz, then you can drop the multiplier to 10x and run it at 2.5ghz with good ram at 250mhz. (Mind you, my last last cpu was a 3500+ that would not budge from stock speed )
If you don't want to shell out for good ram, you can place a memory divider on it and still overclock, running the ram at it's max speed, but the ratio won't be 1:1 and you may or may not suffer some performance loss, but this is not a critical factor unless you ram is really bad/slow. In any case, you need to get it into dual channel configuration and up to at least DDR400, preferably at Cas2 timings.
Before you start googling, remember that this system is superceded and search results are going to predominantly show newer and incompatible hardware, so don't go ordering stuff until you are sure it's for your system.