If you love gaming, you should sell the GX 280 and get something else.  The small form factor cases heat up too much during gaming and they have limited upgrade options especially the old GX 280 with the Pentium 4.  There is really no upgrade path for the processor and with only a 160 watt power supply, there is no option here either for a video card.  

USFF Cannot use anything.  A Silent ASUS 5450 is max.

I'm using a low profile NVidia GeForce 8400 GS 1 GB works like a champ.....

hey.... can it play Crysis 3 on that card? How much ur Ram and what processor did u use while play Crysis ?

Not sure if you can play Crysis.  Have played Age of Empires, Minecraft, SIMs and TF2.  Running with 3.2 Ghz processor and 2 GB Ram

The 5450 is a better card and much newer than the 8400.

Quite Certain that the 8400 is not applicable to Crysis since its dirt slow.

 The 5450 is not an ULTRA card either but it at least runs in Low Settings at 1024 x 768

Minimum System Requirements:
OS - Windows XP or Windows Vista
Processor - 2.8GHz or faster (XP); 3.2GHz or faster * (Vista)
Memory - 1GB RAM or 1.5GB RAM (Vista)
Video Card - 256MB
Hard Drive - 12GB
Sound Card - DirectX 9.0c compatible

Recommended System Requirements:
OS - Windows XP / Vista
Processor - Intel Core 2 Duo @ 2.2GHz
Memory - 2GB RAM
Video Card - Nvidia GeForce 8800 GTS/640 or similar

8800 GTS has 96 stream processors and a 320-bit memory aka 40x faster than 8400GS.

* Supported Processors: Intel Pentium 4 2.8GHz (3.2GHz for Vista) or faster, Intel Core 2GHz (2.2GHz for Vista) or faster, and other similar CPUs.
** Supported chipsets: Nvidia GeForce 6800 GT + or similar GPUs.

Feature Support

OpenGL: 2.1 Aka DirectX® 9

ATI  Radeon™ HD 5400 Series 2010 Release Date.

Memory Interface Width: 64-bit

Memory B andwidth (GB/sec): 12.8 GB/sec

80 stream processors

Standard Memory Config Per GPU: 512MB / 1024 MB DDR3

Feature Support

OpenGL: 3.1 Aka DirectX® 11

sir i have optiplex gx280 
specs
pentium 4 3.0ghz
1Gb ram
windows 7 32 bit edition
its tower
can nvidia quadro fx 570 would work with it i am going to buy i

DELL Part No. WX397

Description: DELL - NVIDIA QUADRO FX 570  will work in a GX280 Tower HOWEVER you have to upgrade the power supply.

Only the 2nd Generation GX280 Tower will work.

Skydive Wont Work easily You have to hack the case to get a regular power supply to work.

The Skydive case only has 250W power supply.

2ND Gen Full Tower GX280 which is the same as GX620 Tower will work.

If its a GX620 and NOT a GX280 it will have a 305W power supply.