Posting here for others with a similar predicament.
My 5,1 slots were basically maxed out. I have a Sapphire Pulse RX580 8GB and despite being one slot, it’s still huge and had very little clearance. Someone in this thread recommended the Sonnet cards being able to squeeze in, so here’s my experience installing it.
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TL;DR: worked right away with no changes necessary. Martin Lo OpenCore 1.0.2 beta with Monterey 12.7.2.
As others have mentioned; the Sonnet fits above a big GPU in a machine where all other card slots are used but it’s a TIGHT SQUEEZE, and I mean EXTREMELY TIGHT.
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It got stuck on the GPU fan which is no good since those are SMD caps clicking against it. I did the following to alleviate that
- added washers to the screws for the mounting bracket to raise up the screws
- trimmed all long through-hole component leads on the bottom of the PCB (with precision cutters)
- Shoved a little piece of 3M foam tape in the corner
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But after all that, the GPU fan was still gonna catch on some of the SMD caps.
Hilariously, I shoved a 1.5mm thick guitar pick between the fan housing on the GPU and the back of the Sonnet card and that helped it clear the GPU fans entirely.
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There is minimal mechanical strain on the devices in my slots above the Sonnet. If anything, the most strain is going to be on the Sonnet card itself.
That being said: plug and play. Worked immediately with no issues.
I thought this card did 10 Gbps speeds but it’s USB 3.0 / 5 Gbps which is my mistake. At first I thought I had something configured wrong before realizing it was just the specifications of the card. And yes, I am using genuine 10 Gbps USB C to USB A cables that I have tested the speeds of on other machines.
Still, with an external SSD USB drive, I still get faster speeds than an internal SATA SSD since the cMP 5,1 is locked to SATA II speeds.
Attached are some DiskMark results showing:
1) SanDisk Extreme USB C SSD 1TB into the Sonnet
2) same drive into USB 2.0 port
3) and a new old stock 2019 Crucial MX500 SATA SSD installed in the machine (Samsung EVO 860 had essentially the same speeds).
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Outside of DiskMark, I am able to copy roughly 50GB of data off the SanDisk external SSD to the Mac Pro internal drive in about 3~ minutes. Love it.