Install EVGA 9800GT & Cougar 700W P.S.U on OptiPlex 755

Hi Mr Max,

Provided that PSU has the correct connectors for your system, it should be fine. It's not a matter of whether the motherboard can "handle" the new PSU, since the 24-pin connector should provide the correct voltage and amperage.

2 Slot Cards WILL NOT FIT.  Single Slot cards fit fine.

AKIMBO means It WILL NOT FIT.

GeForce 9800 GT Part Number 512-P3-N975-AR Core Clock Speed 600MHz Processing Cores 112 Memory Clock Speed 1800MHz Memory Bandwidth 57.6GB/sec Shader Clock Speed 1500MHz Bus PCI-E 2.0 Interface DVI-I, DVI-I, HDTV-7 Product Warranty Limited Lifetime warranty upon registration

GeForce 9800 GT Superclocked Part Number 512-P3-N976-AR Core Clock Speed 650MHz Processing Cores 112 Memory Clock Speed 1900MHz Memory Bandwidth 60.8GB/sec Shader Clock Speed 1620MHz Bus PCI-E 2.0 Interface DVI-I, DVI-I, HDTV-7 Product Warranty Limited Lifetime warranty upon registration

GeForce 9800 GT AKIMBO Part Number 512-P3-N978-AR Core Clock Speed 600MHz Processing Cores 112 Memory Clock Speed 1800MHz Memory Bandwidth 57.6GB/sec Shader Clock Speed 1500MHz Bus PCI-E 2.0 Interface DVI-I, DVI-I, HDTV-7 Product Warranty Limited Lifetime warranty upon registration

GeForce 9800 GT Part Number 512-P3-N980-AR Core Clock Speed 600MHz Processing Cores 112 Memory Clock Speed 1800MHz Memory Bandwidth 57.6GB/sec Shader Clock Speed 0MHz Bus PCI-E 2.0 Interface DVI-I, DVI-I, HDTV-7 Product Warranty Limited Lifetime warranty upon registration

GeForce 9800GT AKIMBO Part Number 01G-P3-N983-AR Core Clock Speed 600MHz Processing Cores 112 Memory Clock Speed 1800MHz Memory Bandwidth 57.6GB/sec Shader Clock Speed 1500MHz Bus PCI-E 2.0 Interface DVI-I, DVI-I, HDTV-7 Product Warranty Limited Lifetime warranty upon registration

GeForce 9800GT AKIMBO Superclocked Part Number 01G-P3-N984-AR Core Clock Speed 650MHz Processing Cores 112 Memory Clock Speed 1850MHz Memory Bandwidth 59.2GB/sec Shader Clock Speed 1625MHz Bus PCI-E 2.0 Interface DVI-I, DVI-I, HDTV-7 Product Warranty Limited Lifetime warranty upon registration

Thanks to God everything is working fine, thanks for both of you, & the info you shared, ,I was worried about the aging components of the motherboard & whether it can handle the stress under heavy loads or not. as the original P.S.U didn't have a PCI-E power cable, which means the system wasn't designed for graphics cards that are power hungry.

Good to hear. Thanks for posting back.

Dual Slot cards are the biggest problem. They don't physically fit into the case.

If the card is too long it may be impossible to get the PCI-E power connectors in.   Also be careful about the SATA power connections being right angle for the hard drives.  Its possible to break off the power connections closing the cover when the sata power is not the Right angle low profile variety.