ATI Radeon 7970 Ghz Edition

After considerable research (for example, see http://http://www.tomshardware.com/reviews/radeon-hd-7970-overclock-review,3186. html), decided to buy Sapphire Vapor-X 6 GB Gz 7970. Also, decided to modify chassis (cut sheet metal in optical drive bay and side panel seal for cable routing) in order to integrate 2nd PSU. Purchased 15-pin SATA to 4-pin Molex cable for ATX BOOSTER power supply trigger (enables 2nd PSU to mirror Mac Pro power supply state). With this 450 Watt PSU, the 7970 now has the appropriate power...

However, after a day of 3D gaming testing, I found the Vapor dual-fan cooling design to run hot under minimal loading (70 C, for example), even with its very noisy fans at full speed. My Arctic-cooled 6970 runs at least 10 C cooler performing the same basic tasks. So, I am going back to the Arctic 7970 after-market cooler for this Sapphire 6 GB card - and cutting the plastic Mac Pro chassis PCIe card guide/retainer to accommodate the extra length of this card/cooler combination.

I am configuring a 3-screen (matched Samsung 3D HDTVs) Eyefinity configuration using this card, since Active mini-DisplayPort to HDMI Adapters finally appear to be available.

Excessive Mac Pro chassis heat can be an issue when running Bootcamp, since Apple does not support any type of PC-based SMC fan control utility, and the Bootcamp fan settings barely change speed of fans as heat increases (sound/noise versus heat decision). Third party tools supporting the Mac Pro 5,1 chassis do not exist (for example, MacFan0_65 stopped working with the introduction of the 5th Mac Pro chassis fan).

Among all current DX 11 games, Crysis 3 appears to need and use the MOST CPU/GPU resources - quite a test for the entire Mac Pro cooling system.

With my 6 GB 7970 and max graphics settings, TriDef Ignition's great S3D renders 18-30 fps (full frame 1080p24). However, even with my Arctic cooler 7970 mod, my GPU max temperatures reach 80 C, while my 3.33 GHz 6-core (W3680 Xeon) CPU max temps reach 90 C! Meanwhile, the chassis fans, including the CPU Exhaust fan, barely increase above their minimum settings...

I decided to try using external fan (see http://www.amazon.com/gp/product/B002OJ ... UTF8&psc=1) to help pull air through my overheating CPU and its poorly controlled CPU fan (reversed fan stand, so fan could touch chassis, aligned to CPU Exhaust fan). It has reduced my Crysis 3 CPU temperatures at least 15 C - and my GPU temperatures have also been reduced. In the Mac Pro chassis, the hot GPU air is blown into CPU area, adding to the CPU's own heat. This essential external fan helps exhaust the hot air in the chassis, since no Bootcamp SMC fan control/override exists. I have provided feedback via Apple Feedback web site.

For additional info about HD3D Eyefinity and current limitations with HDMI-based 3D displays, see whyme466 Jan 2013 comments at http://www.tridef.com/forum/viewtopic.php?f=19&t=1862&start=20.

I would love to know where you find the molex power connectors from the power supply in the mac pro 2009?

There are none in the 2009 and later, because they switched over to a SATA DVD drive, and eliminated the 40/80 pin ribbon cables and the Molex connector.

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But today (as opposed to a year ago when this discussion started) there is a 7970 Mac Edition that does not need those funky adapter cables.

From MacVidCards there is a 7970

From Sapphire, there is a 7950

If you have heavy GPU loading (like Crysis 3, running for hours with CPU/GPU full loading), I suspect that adequate card power, and overheating/excessive fan noise may still be an issue with these more Mac-compatible versions, in Mac Pro 5,1 and older chassis.

I am very interested in pending 2013 Mac Pro, but only if Apple fixes Bootcamp issue with unregulated chassis cooling fans, when running heavy loads under Windows OS(s). New design is elegant, and has radically different expandability and cooling approaches, including number of fans. I suspect that GPU options include rebranded R9 versions of 79xx series GPUs (ideally, newer R9-290 option).

Hey Nextech,

I have a 2008 Mac Pro, and just got a Sapphire Radeon 7970 GHz Edition Card to install in it. Question, did you have to do anything on the Diamond Radeon 7970 GHz Edition to get it to work in your 2008 Mac Pro?

Hey nextech, can I safely run the 7970 with both 8 pins off of the power supply or can I do one 8 pin off the power supply and one 8 pin off the motherboard? Do I absolutely have to run the card off of the motherboard?

Have you looked at the September? tests Barefeats.com did on 3rd party highend graphic cards?