Hey all before start pls zorry whit mi bad inglish. Ok, i got a big problem in mi hands mi dad have a 2008 mac pro but whit OS leopard 10.5.8 and the graphic card just dead 3 days ago (8800 nvidia) i can buy a new card (5770 ati) from mac store but the problem its the system version i know the 5770 need snow leopard for work but what happen if i use in leopard 10.5.8 ? i just need time for upgrade to snow leopard , cant do anything for now because the 8800 its dead very very dead so the question is : i can put the 5770 whit leopard 10.5.8 ? just for get time and install the leopard for 100% support ? .I dont have more options right now. Zorry for mi crap inglish again .