open the case and measure it. you need about 7" where the card is going to sit
Card Dimensions: 6.69" x 4.13" x 1.69"
The Ultimate 7750 is bigger than the standard 7750. Sapphire website says it is 185mm x 120mm x 50mm. That is 7.28 inch long and measuring is darn near the same so am hoping some one has experienced an installation.