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MacVidCards GeForce 780GTX - FurMark blinks off 2009 Mac Pro

G

gsloan

macrumors member
Original poster
Jul 6, 2013
69
6
Austin, TX
Just tried running FurMark tonight on my 2009->2010 Mac Pro with an eVGA GeForce GTX 780 modified by MacVidCards, which to my knowledge was a stock-clocked board.

Within a second of running FurMark, the system blinked off. I've had no problems running any games, Luxmark, or Heaven, but FurMark caused an instant shutdown. I've had no other power-related issues with this system.

Looks like I'm going to need an FSP Booster PSU. Evidently, not all 2009+ Mac Pros will be able to run a 780 without running into power issues.

Since MVC has questioned the veracity of my concern, I'd request that anyone who's purchased a 780 from MVC who's got Windows run FurMark's 60 second benchmark and please post your results here. I'd like to see how many others experience the same issue. 10/31 Update - FurMark does NOT power off in OS X, but does under Windows, for me - Curious to see if anyone else has this happen under Windows specifically

Note - I've got no problems playing games, running AE, Unigine Heaven, etc., but FurMark shouldn't blink the system off in a second or two.
 
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Probably not necessary given that Furmark is some of the most insane, sustained stress that you can put on a graphics card. Highly unlikely to encounter that in real-world conditions.
 
Understood - If the system sustained it for 60 seconds, I might be fine with it. But as soon as I saw the test graphics, the system hard shut down. I'm not talking a blink-off after 4 hours of stress...I'd at least like to see it get through 60 seconds.
 
Furmark puts the device into a condition where it uses a way more power that it's TDP. Obviously 2x6-pin cant provide that.
 
It was advertised as being able to run off of internal power. Supposedly, the difference between it and the Titan is that the Titan would blink off on one of MVC's rigs if powered internally and the 780 would not, which is why I assume an external/FSP Booster PSU is recommended for the Titan. By the same token, it may be a good idea for the 780 as well. Just reporting my experience.

My 680GTX ran fur mark without issue.
 
Using 6-8 pin adapters WILL DESTROY your Mac Pro. NEVER use one. EVEN IF the card has been downclocked to use 225W, it can still draw 150W from the 8 pin cable and the other 75W from the 6pin cable and the slot. Is the risk worth 30$?!
 
I'm not using a 6-to-8 cable. MVC modded the card by soldering the additional 2 power connectors to one of the 6. And it's not running down clocked. It came this way from MVC.

What is this $30 solution you mention?
 
sunnyj said:
Did you plug in the 6 pin came on the right side or left side of the 8 pin connector on the gtx 780?
Click to expand...

Not sure I get the question. The 6-pin only fits into one part of the 8-pin connector. The plastic surrounding each pin is shaped to block improper power cable insertion. Regardless, if it wasn't plugged in correctly and only one 6-pin connector was present, there would be no video.
 
gsloan said:
Understood - If the system sustained it for 60 seconds, I might be fine with it. But as soon as I saw the test graphics, the system hard shut down. I'm not talking a blink-off after 4 hours of stress...I'd at least like to see it get through 60 seconds.
Click to expand...

Furmark uses so much power it has literally destroyed cards. It uses far more power than even the most demanding applications. It's not really a good measure of your power needs.
 
It has already been confirmed by MacVidCards and flowrider that pcie booster (6pin) plugged into the 8 pin slot of modded cards (whilst still able to power up) will draw >75W from that slot.

Did some calculations and derived at this:

MacVidCards - GTX285 (running Furmark) total power draw: 223.1W
- PCIE Slot: 60.1W (80% of 75W)
- Booster cable (6pin): 53.0W (70% of 75W)
- Booster cable (8pin): 110.0W (73% of 150W) <- card originally 8+6pin powered

flowrider - GTX780 (running Furmark) total power draw: 230.5W
- PCIE Slot: 56.3W (75% of 75W)
- Booster cable (6pin): 64.6W (85% of 75W)
- Booster cable (8pin): 110.6W (74% of 150W) <- despite using 6 pin booster cable

Seems like power draw is relatively equal (70-85%) over the different slots, which makes sense. So it doesn't matter if your 8pin slot has been soldered to work with a 6 pin cable, the slot will draw power as it wish.
 
ActionableMango said:
Furmark uses so much power it has literally destroyed cards. It uses far more power than even the most demanding applications. It's not really a good measure of your power needs.
Click to expand...

I realize that FurMark has destroyed some cards in the past and I'm not advocating using it as a long-term burn-in tool.

Again, I'm not letting it sit for 4 hours straight - I simply tried to get it through a 60 second "benchmark" and within 2 seconds, the system powered itself off.

I was informed that this card would make it through FurMark while the Titan would not, though it was suggested that FurMark not be run for hours and hours. All I'm saying is that in my particular setup, I didn't make it 2 seconds.

In a nutshell, if Titan needs an external PSU because it fails at FurMark but games fine for hours and hours, by the same logic, the 780GTX needs an external PSU in some systems.

Where can I find one of these external PSUs for $30? I'm seeing 'em at $70+. And I've already got an external optical drive that works fine. ;)
 
Knowing that a piece of software could take down my system like that would make me uneasy. Plus, if/when something ever went wrong with the computer, I'd always look to the video card as being the culprit first. An auxiliary power supply would buy me peace of mind.

Just my two cents...
 
gsloan said:
I'm not using a 6-to-8 cable. MVC modded the card by soldering the additional 2 power connectors to one of the 6. And it's not running down clocked. It came this way from MVC.

What is this $30 solution you mention?
Click to expand...

I'm sorry what?

Your still attempting to draw more than 75W from the 2nd 6-pin, irregardless of how you split that 6 pin power!!!

Tut tut MVC.

:rolleyes:

For reference, my 7950 draws according to iStat

50/40/90W.

I assume the 90W is from the slot, with the 50/40 from the Boost wires.
 
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pastrychef said:
This one is under $30.

* Disclosure: I have never used one and have no idea how well it performs.
Click to expand...

Any others you know of? One of the comments says the PSU is loud...I'd rather add one that doesn't add much noise.

From HardOCP said:
Load Testing Audio Impressions

The ePower Juice Box 450W is a small power supply as it fits into a 5.25" bay which means that its cooling options are going to be limited to 40mm fans. 40mm fans are not generally what one first considers when they think quiet, and for good reason. However, with a good fan controller the Juice Box could still be tolerable if it had good efficiency. That was not the case and the unit was not quiet by any stretch of the imagination. In fact the unit was so loud I wonder if there even is a functional fan controller in these units at all (half sarcastic here). In our tests, the Juice Box was extremely loud on the order of some of the loudest units we have ever had in for review. This noise was not as bad when we had the unit running at room temperature, but as soon as it was moved to 45C and the temperatures began to rise the unit went from a little noisy to screaming Banshee fast.
Click to expand...
And...does anyone have experience mounting one of these? Are there holes you have to punch somewhere to run the cables to the video card?
 
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It might actually be a good idea to report this to MVC since he sold you the card. It would be polite to give him an opportunity to comment in private before airing it here.
 
DanielCoffey said:
It might actually be a good idea to report this to MVC since he sold you the card. It would be polite to give him an opportunity to comment in private before airing it here.
Click to expand...

It might be, but then again, it might not. I appreciate the etiquette lesson. Much obliged.

That being said, I'd like some feedback from the community to see if anyone else has experienced similar issues when running a benchmark that this card was supposed to complete.

Considering that MVC replies to my emails selectively, whenever it's convenient, or never, I feel it's prudent to start a discussion here and have him chime in if and when he decides to.
 
I can report good results with an MVC GPU and FurMark. I recently installed an MVC-flashed GTX 580 without any external PSU. I also run an old GT 120 in the same machine to a third monitor. Although FurMark makes the fans in the GTX 580 spin up something crazy, the card obligingly performs the benchmark and reports good results. At 1600x900, AA off, I'm getting a score of 4510 at 75 FPS.
 
There are a few reviews (none too favourable) about the JuiceBox floating about. Sounds like the Booster is worth the premium.
 
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