A teardown of Apple’s new Mac Studio PC appeared online this week, and the big reveal was there’s an empty SSD slot inside. Apple is notorious for soldering down everything in its computers, and rarely, if ever, allowing post-sale upgrades. Given the size of the Studio and it’s “non user-accessible” design, soldered storage was expected. Imagine peoples’ surprise upon seeing it uses socketed storage. This lead to wild speculation about what Apple could be up to, since there was no official explanation. Some figured it was for storage upgrades, because what else would you do with an empty SSD slot?
Remember though; this is Apple we’re talking about here. Things don’t always work the way you think they will. Multiple outlets have now dug into the issue, and one thing is clear: it’s not for storage upgrades. It’s for Studios that ship with either 4TB or 8TB of storage, which requires two SSDs to be pre-installed.
News of the vacant SSD slot first appeared in a teardown video by Max Tech. He saw the mainboard had two propriety SSD slots; one populated, one empty. He confirmed he could plug the SSD into the second slot, but he didn’t attempt to turn it on after doing that. He also grabbed a removable SSD from the Mac Pro to check if it had the same pin-out, and it did not. This revealed the Mac Studio has its own propriety storage design. Max Tech speculated that Apple might sell “upgrade modules” for that second port, someday.
Next, YouTuber Luke Marini moved the ball down the field by doing a few things. Since he had two Mac Studios, he erased one SSD and installed it in the empty slot of the other one. His wanted to see if he could double his storage from 1TB to 2TB by adding a second drive. The result: an amber light on the Mac Studio, flashing Morse Code for SOS. Next he tried taking the pre-installed SSD from the primary slot, and just moving it to other slot. This also didn’t work, as the system said the SSD was not recognized.
One hint that this would fail is the difference in the PCB below the slots. The populated slot has two Texas Instrument chips and some kind of VRM. The second slot’s PCB area is empty, however. This indicates that the storage on the Studio has to be configured a certain way to function. iFixit was also able to swap SSDs between systems with a DFU Restore, but could never get both slots to function.
Apparently, the SSDs are just “raw NAND” according to Asahi Linux developer Hector Martin. That’s because the storage controller is in the M1 chip, not on the SSD itself. However, he says if you use two SSDs, they will need to be the same size, and maybe even the same vendor. As Ars Technica notes, the SSD controller requires the drives to be configured a certain way, and mixing and matching is a no-go.
Therefore, it seems the second slot is indeed for an SSD, but you can’t just toss whatever you want into it. That said, how would one even acquire a second SSD for the Studio? Apple has said it’s not user-serviceable. Although Apple might sell SSD upgrades in the future, the majority of users won’t be able to upgrade it due to its complex design. You’ll need to wipe your drive to add more storage, and not a lot of users would feel comfortable with that. The bottom line is this: Apple has already said the Studio is not upgradeable, and there’s no reason to think that will change in the future, empty slot or not.