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MacCessories-TN

macrumors newbie
Original poster
Jun 22, 2025
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I'm running a Mac Pro 5,1 (2010 version) with dual x5690s, 128GB RAM and currently an RX 580. It's currently dual booted with both windows 11 and Sequioa via OCLP. Recently, I bought a Sapphire Pulse RX 6700 XT to put in since the 6000 series seems to be the last series of cards that can be ran without a Pixlas Mod, which I have not yet done. I'm well aware of NootRX and and will be trying to install it tonight via OCAT. Here's what i'm experiencing, which i found to be a bit odd, and thought i'd share to get some thoughts.

Upon putting the 6700 into slot 1 and booting, I get no boot chime at all. When running the rx 580 in the same slot, it appears to work just fine. When I put the 6700 in the second 16x slot, I get a chime, but my keyboard doesn't light up like it usually does during the chime and appears not to be working at all. Still no display from the 6700 in either, but a chime from slot 2. The 6700 has not had it's vbios flashed as of yet, since I don't have another pc handy to do that.

I guess what i'm wondering is this:

1) Is there any way around this without flashing the card? Has anyone had any success with just using NootRX and just do a graphics card swap at shut down after implementing those (if that makes sense)?

2) I'm assuming the keyboard isn't lighting up because it's not reaching the stage to initialize those files?

3) If this were a power issue, would I still be getting a chime from either slot?
 
1) Is there any way around this without flashing the card?

To power on a MacPro5,1 with any NAVI 2x GPU, the GPU needs to be flashed with the Syncretic patch previously or the MacPro5,1 firmware will crash and won’t complete the POST. This is a MacPro5,1 only requirement.

So, the answer for your question is NO.
 
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To power on a MacPro5,1 with any NAVI 2x GPU, the GPU needs to be flashed with the Syncretic patch previously or the MacPro5,1 firmware will crash and won’t complete the POST. This is a MacPro5,1 only requirement.

So, the answer for your question is NO.
Thank you so very much! I've been reading your replies to people for a while, and appreciate your thorough answers.
 
Btw, MacPro5,1 with any NAVI GPUs (1x or 2x) will only work up to Monterey - nothing else will work.

After Monterey, NAVI drivers require a processor that support for the family of AVX instructions, which MacPro5,1 Xeons does not have. OCLP does not support NAVI GPUs after Monterey.
 
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