As the 1435 only seems to have 1 PCIe (or 1 PCI-X) slot (see specs in the getting started guide from the 1435 online documentation), <ADMIN NOTE: Broken link has been removed from this post by Dell>  and it's already in use for your SAS5IR controller, there are no more expansion slots to put in any other cards.
  My company has a Dell PowerEdge SC1435, and we would like for some of our employees to be able to occasionally log in to it through Remote Desktop and run a specific 3D application on it.  The 3D application does not have to run well, it simply needs to be able to start and allow simple menu interaction with it.  Is it possible to install a 3D graphics card in the server named above?  Is there room in the case?  Will it cause problems with heat and airflow?   I do not have physical access to the server yet, but I should soon, and I can get more exact measurements of the server then.  Until then all I know is that this is a 1U server with the following specs:   Base Unit:  Dual Core 2212 Processor; 2X1MB Cache, 2.0GHz Opteron, 1Ghz HyperTransport for PowerEdge SC 1435 (222-6400) Processor:  No Second Processor (311-3928) Memory:  1GB 667MHz (2X512MB), Single Ranked DIMMs (311-6416) Video Card:  Broadcom TCP/IP Offload EngineNot Enabled (430-1765) Video Memory:  Riser with 1 PCIe Slot for PowerEdge SC1435 (320-4982) Hard Drive:  250GB, SATA, 3.5-inch 7.2K RPMHard Drive (341-3803) Hard Drive Controller:  SAS 5IR SAS, PCI-Express Internal RAID Adapter (341-3756) Operating System:  Windows Server 2003,Web Edition (420-2967) NIC:  On-Board Dual Gigabit Network Adapter, No TOE (430-2008) CD-ROM or DVD-ROM Drive:  24X IDE CD ROM Drive for PowerEdge SC 1435 (313-4478) Sound Card:  Bezel for PESC1435 (313-4477) Documentation Diskette:  No Hard Copy Documentation, E-Docs ONLY and OpenManage CD Kit (310-8261) Additional Storage Products:  250GB, SATA, 3.5-inch 7.2K RPMHard Drive (341-3803) Feature  Add-in SATA/SAS controller, 2 Hard Drives, RAID 1, PowerEdge SC1435 (341-3961)  
Is it possible to install a 3D graphics card in a 1U PowerEdge SC1435?