Query failed: connection to localhost:9312 failed (errno=111, msg=Connection refused). How high can I go? - macOS Discussions on AppleInsider Forums Toggle navigation All Forums Recent Posts Sign In How high can I go? harpjw Posted: May 25, 2009 4:31PM in macOS edited January 2014 How much of 10.5 can I upgrade to using a:Machine NametiMac G5Machine ModeltPowerMac8,1CPU TypetPowerPC G5 (3.0)Number Of CPUst1CPU Speedt1.8 GHzL2 Cache (per CPU)t512 KBMemoryt1.5 GBBus Speedt600 MHzBoot ROM Versiont5.2.2f4 Comments Reply 1 of 3 macxpress Posts: 5,138member May 25, 2009 6:31PM The latest version of Mac OS X (10.5.7) should run fine. However it will most likely be the highest your iMac can ever go as it appears that Snow Leopard (Mac OS 10.6) will be Intel only. You have enough processing power. If it seems a little slow the only thing I'd do is upgrade the RAM. Other that, you have more than enough to run Mac OS 10.5 (Leopard). Reply 2 of 3 mr. me Posts: 3,221member May 25, 2009 6:31PM MacOS X 10.5.7 is not a new OS. It is only the latest update to MacOS X 10.5. You iMac will accept the latest update to MacOS X 10.5, whatever that might be when you read this. Reply 3 of 3 dfiler Posts: 3,420member May 29, 2009 11:48AM All versions of Mac OS X will currently run on that machine. When 10.6 (snow leopard) is released later this summer, it will not run on that machine.In other words, you can use the latest version of 10.5. Sign In or Register to comment.