Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

ApplePearGrapefruit

macrumors newbie
Original poster
Apr 19, 2023
13
6
Good evening everyone! Yesterday I picked up a Sapphire R9 280X to replace the HD 5770 in my 4,1 Mac Pro. It has a 6 and 8 pin power connector, so I bought two adapters to properly power it. For the 8 pin, I got a 2 mini 6-pin to 8-pin adapter and for the 6-pin, I got a SATA adapter to use from the HDD slot. I swapped in the new card and hooked everything up and turned on the computer and the graphics card was powered up. Next thing I know, I smell something terrible and see smoke coming out of the Pro. After quickly yanking out the power cord, I took everything out and found that the SATA port had melted to the adapter. I had watched a video that said that this was okay to do, so I guess I'm just curious why this happened? Am I just really dumb or does the card draw to much power or am I overlooking something? Also, is it ok for me to power it back up with the melted SATA port? Thanks in advance!
 

tsialex

Contributor
Jun 13, 2016
13,065
13,275
Good evening everyone! Yesterday I picked up a Sapphire R9 280X to replace the HD 5770 in my 4,1 Mac Pro. It has a 6 and 8 pin power connector, so I bought two adapters to properly power it. For the 8 pin, I got a 2 mini 6-pin to 8-pin adapter and for the 6-pin, I got a SATA adapter to use from the HDD slot. I swapped in the new card and hooked everything up and turned on the computer and the graphics card was powered up. Next thing I know, I smell something terrible and see smoke coming out of the Pro. After quickly yanking out the power cord, I took everything out and found that the SATA port had melted to the adapter. I had watched a video that said that this was okay to do, so I guess I'm just curious why this happened? Am I just really dumb or does the card draw to much power or am I overlooking something? Also, is it ok for me to power it back up with the melted SATA port? Thanks in advance!

A SATA connector can provide 54W max, with no reserves, while the 6-pin mini PCIe of the backplane is rated to 75W with a tolerance for something around 110W before the SMC cuts out power with an emergency shutdown.

The moment the GPU had power draw of over the 54W for the 6-pin PCIe connector, this would fail. Unfortunately, no surprise here.
 

ApplePearGrapefruit

macrumors newbie
Original poster
Apr 19, 2023
13
6
A SATA connector can provide 54W max, with no reserves, while the 6-pin mini PCIe of the backplane is rated to 75W with a tolerance for something around 110W before the SMC cuts out power with an emergency shutdown.

The moment the GPU had power draw of over the 54W for the 6-pin PCIe connector, this would fail. Unfortunately, no surprise here.
Thanks for the reply! I watched this video:
and after reading the comments, somebody mentioned this issue. If only i would have read the comments beforehand :(
 

avro707

macrumors 68000
Dec 13, 2010
1,829
1,166
Never trust random Youtube videos, always watch a number of them or ask here first.

I wonder if it's time to find a well looked after 5,1 or something much newer? After the smokescreen I wouldn't chance it.
 

ApplePearGrapefruit

macrumors newbie
Original poster
Apr 19, 2023
13
6
Never trust random Youtube videos, always watch a number of them or ask here first.

I wonder if it's time to find a well looked after 5,1 or something much newer? After the smokescreen I wouldn't chance it.
Lesson learned but I might not have taken your advice. Popped back in the 5770 and she powered right up. Still running just as good as before (minus a hard drive bay).
 

tsialex

Contributor
Jun 13, 2016
13,065
13,275
For GPUs around 225W power draw, the best way to provide power, when you don't want to do a Pixla's mod, is to install an eVGA PowerLink, works for most R9-280X, VEGA 56, GTX 1080Ti with reference design.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.