Not any more. About a year ago the 8800GTX was the best card available, by far. That led to games like Crysis that were indeed optimized for nVidia. These days however ATI has the lead and game developers pay a lot more attention to ATI cards than before.
In general, in the $150 range the HD 4850 rules. That's especially true because HD 4850 Crossfire scales better than 9800GTX+ SLI and because HD 4850 Crossfire works on Intel chipsets (P45, X48) which are usually better than SLI motherboards.
Anyway, you'll be happy with either HD 4850 or 9800GTX+. Just avoid the 9600GT, that one is weaker.
ok but what about PhysX because some pepole say that Geforce support PhysX but really I do not know what this PhysX is and is there any difference between cards that support PhysX and other that do not it support it in Games and graphic programmes performance because I love games very much and I want the card which provides higher performance in games??
There are two APIs for physics calculations. One is called PhysX and implemented in nVidia cards. The other is called Havok and you get it with ATI cards. Some games use PhysX (can't think of an example right now, but there's lots of them), some use Havok (e.g. Diablo 3). Either way, with a good CPU you can get physics support through software, i.e. done by the CPU. It really shouldn't be a factor when you choose your graphics card.
The Radeon HD 4850 continues to be a better buy than NVIDIA's GeForce 9800 GTX, even if both are priced at $199. The overclocked, 55nm 9800 GTX+ manages to barely outperform the 4850 in a few titles, but loses by a larger margin in others, so for the most part it isn't competitive enough to justify the extra $30. The 4850 also uses significantly less power than the 9800 GTX+, and AMD was quick to point out that by the time the 9800 GTX+ ships that it will also have factory overclocked 4850s. That should make things even more interesting, because honestly, a factory overclocked Radeon HD 4850 is far more attractive to us than an overclocked GTX+.
That being said, the difference between those two cards is minimal, so don't worry about it. The 9800GTX+ got 31.6 fps, better than HD 4850's 29.8 fps, in Crysis at 1600x1200 with no AA on Anandtech's PC. With AA enabled, the HD 4850 wins. At 1280x1024, either of those cards should give you at least 40 fps in Crysis, so I think you'll enjoy playing.
Interface PCI Express 2.0 x16
Chipset Manufacturer ATI
GPU Radeon HD 4850
Core clock 625MHz
Stream Processors 800 Stream Processing Units
Memory Size 512MB
Memory Interface 256-bit
Memory Type GDDR3
DirectX DirectX 10.1
OpenGL OpenGL 2.1
HDMI 1 via Adapter
TV-Out HDTV / S-Video / Composite Out
RAMDAC 400 MHz
Max Resolution 2560 x 1600
CrossFire Supported Yes
Cooler With Fan
System Requirements 450 Watt or greater power supply with 75 Watt 6-pin PCI Express power connector recommended (550 Watt and two 6-pin connectors for ATI CrossFireX technology in dual mode)
Power Connector 6 Pin
Dual-Link DVI Supported Yes
Windows Vista Certified for Windows Vista
HDCP Ready Yes
Package Contents 900241
DVI to VGA/D-sub Adapter
DVI to HDMI Adapter
S-Video to Composite Adapter
Parts Lifetime limited
Labor Lifetime limited
I just realized. Your P5Q-E supports two HD 4850 cards in Crossfire. It won't support two 9800GTX+ in SLI. That's an excellent reason for you to prefer the HD 4850. When one card is not enough any more, you won't need to buy an expensive new video card or a new motherboard, you'll just spend another $100 or so on a second HD 4850. If it's $150 now, I'm sure it will be under $100 a year from now. I'm assuming your PSU does satisfy the requirements for HD 4850 Crossfire (550W or more, two 6-pin connectors).
thank you very much and after reading your helpful answers ,I prefer HD 4850 but
I heard that when I use card too much it becomes very hot so it can be corrupted easily and also it will have shorter life because this problem..is that true and does this problem present also in HD 4870 ??
Yes, in general, single-slot graphics cards can get hot. We've seen that with HD 4850, and before that with 8800GT.
If your case has excellent cooling you don't have to worry about that. If not, get a dual-slot card.
There are dual-slot versions of the HD 4850 now. They have a vent through which the heat can get out of the case immediately, and better heatsinks and fans. The HD 4870 cards are all dual-slot AFAIK, and they're faster too, but they cost more.