macpro burning through hard drives -- ? video card pulling too much power?

[Uli Wienands]

Hmm... it isn't obvious how "drawing too much power" would endanger your 
drives before the power supply gives in. Per EveryMac.com this Mac Pro 
can support up to 300 W total in the PCI bus. But the 200 W for your 
card seems to apply only for heavy duty GPU running, like BitCoin mining 
and it draws much less even when gaming. Unless your PCI is already 
filled up with other stuff, based on the numbers the bus should be able 
to power the card by itself.

I'd be suspicious whether the card somehow puts the extra power you 
provide to it back onto the bus, thereby putting overvoltage on some 
sensitive items like your HDs. Is the extra power you provide 12 V or 5 V?

I have two MacPro's of the same vintge. Merrily humming along with 2 HDs 
in each of them & my swapping out disks regularly to try things out. Has 
yet to kill a disk. I would be highly suspicious of the card. Unless it 
runs without the extra power I'd toss it.

Just my $0.02,

Uli

On 1/7/19 8:02 PM, Ken Cunningham wrote:
> This has nothing to do with Macports, but  there are many people here who know stuff about this...
>
> About six months ago I put a new Metal-capable Sapphire HD 7950 video card in my 2010 MacPro (8 processors) to run Mojave. It required two extra power cables to give it all the extra juice it needs, in addition to the usual bus power. It seems to pull up to nearly 200W according to Tom's hardware <https://www.tomshardware.com/reviews/radeon-hd-7950-review-benchmark,3207-9.html>.
>
> Since then, I have bricked three SATA hard drives on that MacPro, two older 2TB ones (2012 era) but one 2016 4TB SSHD that was pretty new.
>
> All three of the drives just disappeared off the desktop unexpectedly with a message about not powering them off properly, and then at reboot would not spin up, and never did work again.
>
> I'm suspicious that the 7950 is pulling too much power and causing the SATA hard drives to fail. I also have an AJA Kona 3G in that machine that pulls 20W.
>
> Anyone seen this?
>
> Ken