Mac Pro 1,1 not sleeping El Capitan

[My iPhone3G]

I have the original Nvidia Gt 7300 in it currently with 2 2.66 Duos with 16GB of ram. If I press sleep the computer kinda locks up the screen but things still move? Its strange. It will do a screen saver (at like 10fps) but I can not sleep the machine. Is it the GPU?

 

[CapnDavey]

ATI 4870's can be had for as little as 25 dollars on eBay they are easy to flash and work OOB without boot screen. upgrade that video card the 7300 blows on the newer systems ( unsupported )

 

[My iPhone3G]

Yeah I had a 5770 sitting around. Plugged it in and it works. Decent little system after all the upgrades.

 

[CapnDavey]

dig around you can flash most of those as well