MAC PRO 2007 PCIE POWER CABLE INSTALL
MAC PRO 2007 PCIE POWER CABLE WINDOWS 10
MAC PRO 2007 PCIE POWER CABLE PRO
MAC PRO 2007 PCIE POWER CABLE PC
MAC PRO 2007 PCIE POWER CABLE FREE

Yes, I'm aware of having different grounds. If you're an electrician or and electrical engineer, you're going to be wincing and cringing at your screen at some of my following choices.

MAC PRO 2007 PCIE POWER CABLE FREE

The PSU in the eGPU kit! It was small, quiet, and free for me to use. In fact I had a spare PSU that was powering an RX 580 all along. In fact, there are 5 1/4' PSUs available to fit in the Super Drive drive bay I could have purchase. Sure I could have looked for a better power delivery unit for the Mac Pro. I still needed more power from the GPU.īut remember I'm cheap. All of them had either shutdowns, or crashes depending on the power usage setting in Wattman. I tried 6-pin to 8-pin adapters, I tried multiple SATA to 6-pin (opens in new tab) into another 2圆-pin to single 8-pin adapters. I tried various cable adapters that I had lying around at first to see if I could sap power from other system components to feed the GPUs. I knew that I needed more power to be delivered to the cards. To my amazement, it worked! However, even though the machine no longer shut down, I was getting very frequent crashes and screen locks.

MAC PRO 2007 PCIE POWER CABLE WINDOWS 10

To test this, I used the Windows 10 AMD program called Wattman to lower the power usage of each GPU by 30% and then I reran my Crossfire test.

MAC PRO 2007 PCIE POWER CABLE PRO

Either the cards were too starved for power, or the PSU on the 2009 Mac Pro wasn't up to the task of supplying enough power to the GPUs even at the lower wattage. It was during the usage of Crossfire that my system would simply shutdown.

MAC PRO 2007 PCIE POWER CABLE INSTALL

I was excited to try to use both GPUs in Crossfire mode under Windows 10 so I switched to my Boot Camp install and ran some tests. My two GPUs ran OpenCL based applications insanely quickly. I had to make extra special care to not make the spacers too wide as I was putting pressure on the PCIe pins on the lower most GPU. I used two plasticized grommets I had from some AV cables as the spacers. Secondly, I added two spacers in between the GPUs so that it gave me just a bit more space to all some more airflow for the bottom most GPU. This removal of the back-plate gave me just enough space for the fan on the lower most card to spin freely. First, I removed the GPU back-plate on the upper most card. I didn't want the bottom GPU over-heating. So stacking them not only restricted air flow, but it also physically stopped the fans of the lower most card from spinning. My RX 580s had regular fans blowing onto the heat sink. A blower style fan can have closely stacked cards since it suck in air from a fan at the front end of a GPU and then 'blows' air across the heat sink out the back of the card.

This PCIe problem wouldn't have been an issue if the GPUs came with what is called a 'blower' style fan. So I needed to run both cards in the adjacent slots. There are other slots as well but those run at a slower bus speed and would cause issues while running the two GPUs in Crossfire mode under Windows 10. Interestingly, the Mac Pro ALMOST does this too, except that there is too little of an interval between the PCIe slots. Most manufactures of motherboards deal with this nicely by placing their PCIe slots at intervals where an installed GPU will not interfere with another equally capable PCIe slot.

MAC PRO 2007 PCIE POWER CABLE PC

This means that in a normal PC based motherboard, the GPU card will take up two slot positions when mounted. The most immediate issue was the slot placement of the two 16x PCIe ports on the 2009 Mac Pro. Why not just remove the RX 580 from the eGPU enclosure and put it into my 2009 Mac Pro? I'd have double the compute power than I had using a single GPU and since I use Boot Camp to run Windows 10, I could harness the second GPU to run in Crossfire mode (a special way for 2 or more GPUs to split graphical workloads) for gaming in Windows! The problems and solutionsĪlthough the overall idea was simple, in practice I ran into some issues. One of them was being used by my own RX 580. The 2009 Mac Pro has two 16x PCIe ports on the motherboard. The ideaĪlthough I could have continued to used the eGPU kit, the performance delta when compared to the Mac Pro had me just leaving it unused for some weeks. Overall, the eGPU on TB3 ran about 25% slower than the GPU in the Mac Pro. And although it does it's job, the performance relative to the AMD RX 580 running directly on a PCIe port on my much older Mac Pro was a bit disappointing.

For my testing I received one of the Apple eGPU development kits to run on a borrowed Skylake based MacBook Pro via the Thunderbolt 3 port.

Mac pro 2007 pcie power cable