Hey! I totally get the frustration with a sluggish Mac. I've been there with my own 2015 15-inch, and honestly, an SSD upgrade is the single best thing you can do for these legendary machines.

Before we dive into the hardware, you gotta be careful about the power management issues. Many standard NVMe drives aren't optimized for macOS, which leads to your battery draining while the lid is closed or the laptop getting toastier than it should. Also, avoid those cheap, unbranded green adapters you see on auction sites; they often cause "kernel panics" or failure to wake from sleep.

Here's what I recommend based on my experience:

1. **The Adapter:** Apple uses a proprietary connector, so you definitely need an adapter. I strictly suggest the Sintech NGFF M.2 NVMe SSD Adapter Card for Upgrade 2013-2017 MacBook. It's the most stable one out there, period.
2. **The Drive (Battery King):** For the best balance of speed and efficiency, get the SK hynix Gold P31 1TB PCIe NVMe Gen3 M.2 2280 Internal SSD. It's famous in the Mac community for having the lowest power draw, which keeps your MBP running cool.
3. **The Drive (Performance):** If you want raw stability and don't mind a slight hit to battery life, the Samsung 970 EVO Plus 1TB NVMe M.2 Internal SSD is a classic choice, though make sure the firmware is updated.

That said, make sure youre running at least macOS High Sierra before you start, as that update includes the necessary firmware to actually recognize NVMe drives. Good luck with the surgery! Let me know if you need more info.

Jumping in here because I've seen way too many people brick their sleep-wake functions by picking the wrong drive! Quick question—before I give advice, can you clarify if you've already updated your macOS to at least High Sierra or later? This is crucial because the firmware update included in those versions is what actually enables NVMe support on the logic board.

I remember back when I first tried upgrading a client's machine with a generic drive; it was a total nightmare of kernel panics until I realized the firmware wasn't ready. Since you're on a budget, you might want to consider the SK hynix Gold P31 1TB PCIe NVMe M.2 SSD. It’s legendary for being one of the most power-efficient drives out there, which is a lifesaver for the mid-2015 battery life. FWIW, it runs way cooler than the higher-end Gen4 drives that just waste energy as heat in these older Macs. Just make sure to grab a reliable adapter like the Sintech NGFF M.2 NVMe SSD Adapter Card for 2013-2017 MacBook to ensure a stable connection. Let me know about that macOS version!

Spot on about the firmware - that step is non-negotiable or the NVMe drive wont even show up. Tbh, looking at the market right now, you really have to weigh the controller efficiency because these 2015 models can get pretty hot. Some brands just handle the macOS power states way better than others, which is huge for battery life. Based on my experience and what is currently available on the market, here is how the top contenders stack up:

• SK hynix Gold P31 1TB NVMe
• This is the undisputed efficiency king. It runs cooler and draws less power than almost anything else available, making it the best pick for keeping your battery life healthy.
• Western Digital WD Black SN750
• A very stable choice with a proven track record in Macs. Just make sure you get the standard version, not the newer Gen4 or SE models which can be hit or miss with compatibility.
• Sabrent Rocket NVMe PCIe Gen3
• A solid mid-range pick that uses a Phison controller known for being pretty reliable with the sleep/wake cycles on macOS. Basically, you want to avoid the temptation of buying the newest Gen 4 drives. The market is flooded with them lately, but they are a total waste for a 2015 machine since you are capped at Gen 3 speeds. They also tend to run much toastier. Stick with a high-quality Gen 3 drive that has dedicated DRAM and you will feel like you have a brand new laptop, right?

Hi there, I've been thinking about your question for a few hours now, and I wanted to chime in with a slightly more cautious perspective. While the previous reply mentioned some popular choices, I'm always a bit worried about the 'hacker' approach of using adapters because they can occasionally cause sleep/wake issues or extra battery drain if you aren't careful.

Check out these resources if you want a more stable, 'official' feeling experience:

• There's a great resource at MacSales (OWC) specifically for their OWC 1.0TB Aura Pro X2 NVMe SSD. It’s designed specifically for the proprietary Apple connector, so you don't need any extra adapters. Honestly, it's the safest route for a beginner.
• Pro tip: If you do go the M.2 route, you might want to consider the SK hynix Gold P31 1TB PCIe NVMe Gen3 M.2 2280 Internal SSD. It's legendary in the Mac community for being incredibly power-efficient, which helps keep the heat down in those older MBP chassis.
• You should definitely look at the guides on iFixit. They have a specific walkthrough for the Mid-2015 model that is super helpful.

I believe sticking to a Gen3 drive is safer than trying to force a Gen4 drive in there—it's just more stable, tbh. Make sure to have a Pentalobe P5 Screwdriver and a Torx T5 Screwdriver handy before you start! It’s a bit nerve-wracking to open up your main machine, so just take it slow. Hope this helps!

No way, I literally just dealt with this yesterday. Small world.