Multiple question regarding about processor/ video card

[Wayne]

my video card is 9600GT 1GB from point of view
It has:
64 CUDA cores (stream processors)
Core clock = 650mhz
256 memory bits
shader clock = 1625mhz
mem clock = 2x800mhz
dedicated mem = 1024MB GDDR3
Slot = Pci-E 16x gen2 (2.0).

I have 3 questions about it:
1. does it have good especifications?
2. Sometimes, when i'm running a JAVA application/game, my video card drivers crashes and returns to normal, screen also become black, what is this?
3.Are there tips that i can improve my performance (in drivers settings)? because i've been getting some annoying lag in GTA IV

Processor:
Phenom II X6 1055T 2.8ghz 6 core.

2 questions:
1. it's there a way to use 2 or ALL cores in GTA:SA in all times? because i've been getting some lagspikes.
Is there some sort of patch? because i hate minimizing and setting them by ctrl + alt + del.
2.Is there something that i can enhance the peformance? because sometimes i feel like it's slow as a P4.


And one last question about GTA SA
Why GTA SA is so buggy at 40+ fps?

[Kessu]

GPU:
1st: No
2nd. Drivers crashing, update them and remove ALL GPU drivers you have had before.
3rd: Drop the settings in GTA IV.. I'd rather not touch nVidia control panel unless you know what your doing.

CPU:
1. You don't need more than 1 core of it to run SA with no lag. It's the video card that causes lag if drivers are crashy.
2. I got the CPU at 4GHz... Overclocking is a possibility, but I would not recommend it again unless you know what your doing


Edit: To the GPUs first question, I can specify why:
8800 GT / 9800 GT is the "oldest" and "worse" video card what runs PhysX lagless
256 memory bit, that's only good thing.
GPU Memory: 1Gb on that video card. Just no. It actually loses performance because of the amount of Memory but it can't use it.
MHz doesn't matter in video card anyways.