First off, let me say that I am excited to post for the first time in a long time. I was a registered user about 10 years ago when I and a cadre of fellow Pismo PowerBook owners were discussing how to max them out. The Pismo finally gave up the ghost about 5 years ago and I purchased a 2008 Mac Pro. I never experienced performance issues with my Mac Pro until Yosemite, which really bogged it down. The poor performance put me on an upgrade kick. I may purchase a 2010 Mac Pro sometime in the future for access to the faster architecture, processors, and RAM, but in the short term I intend to upgrade my 2008 in ways that will be transferrable to a newer Mac Pro - namely, a new GPU and possibly a PCIE SSD. (Incidentally, I found the thread on use of Apple PCIE SSDs in the adapter card to be insanely helpful.) I am very interested in the GTX 970. I have been looking for a powerful GPU that is still power efficient with low TDP, and the 970 looks like a perfect upgrade from my flashed ATI 6870. To date, the Mac Pro forum has spilled most of its ink over the GTX 980. Can anyone who is using a flashed or unflashed GTX 970 please share their experiences or recommendations that might help me make a decision about how to proceed. I am interested in these two cards from newegg right now: http://www.newegg.com/Product/Produ...87075&cm_re=nvidia_970-_-14-487-075-_-Product http://www.newegg.com/Product/Product.aspx?Item=N82E16814127835&cm_re=GTX_970-_-14-127-835-_-Product I am leaning toward a reference clock speed with good cooling to minimize temps inside the case. Has anyone had a good experience with either of these cards or another card, or had any luck flashing? I have not heard any news from MacVidCards about flashing the 970, so I am also on the fence about whether I ought to buy now and flash later or wait to purchase a known "flash-friendly" model. Finally, a word of thanks to everyone in this forum and the whole MacRumors community. These forums have been an unparalleled source of quality information about upgrading, modding, troubleshooting, etc. for many years, and ultimately that's why I stopped lurking and decided to re-register.