15" MBP 2015 DG 4TB SSD upgrade

@AnnoniMoose - Last year I threw out 30 M.2 SSD's and a few different adapters, many Sintech.

The generation of OWC drives is likely what you noted as the early ones did have issues.

Part of the problem is similar to what got Intel into trouble pushing density without improving the process Node so the cell logic spacing is smaller and runs cooler.

The biggest issue with M.2 SSD's is the simple fact Apple has lines between the SSD controller and the logic board the M.2 and adapter have no concept of dealing with. These lines involve sleep mode, garbage collection and TRIM services.

Yes! day one the M.2 SSD will work! But as you use your system if you put your system to sleep (closing the lid) while some of these processes are running you can leave incomplete recovery of the cell block.

Think of it this way You have a 1000 bullet chamber with a few bullets scattered so the chance of getting shot is present but its not easy! Now let's reduce the chamber to 500, then 250 and then 75. The probability increases! So as the drive is more used and full the risk increases!

Now someone who fails to be a good at backing up may end up having a sizable loss. If you are a pro under deadlines getting hit by this bullet is not what you want!

I deal with advanced amateurs, students and pro's who do photo, video and music production. Which is likely why I see the failures more so than others.

The issue of SSD heat is a bit over blown The flash chips run better when on the upper warm side (not ultra hot) the controller runs better being cool!

The write operation to the flash is the heaviest heat point. So a few hits at a time no big deal a massive write can be a real cooker!

The physical size of the blade SSD also creates an issue. A low density drive (128, 256, 512 GB) has more space to work within, a high density drive (1,2 & 4 TB) less as well as the flash cell logic density also needs to be considered (9, 7 or 5nm)

Now the next issue is shedding the heat! We have two elements here Mass and Heat Movement. Many people just think a larger heatsink Mass is all thats needed, pasting a thick strip of copper or metal block, that works to a point for small write/read operations. But, once the heatsink is at its thermal equilibrium with the chips it offers no further benefit!

Yes, just like a tea kettle over time the heat will radiate off but the speed is the question! It is just not fast enough here!

So that pushes us to Heat Movement transferring it to the external world in some way. Just like a CPU chip we can go full tilt with a set of heat pipes to move the heat to a second mass which has a set of fins with a fan blowing across or we can use a heat sink which has a large air surfaces either leverage the systems fan to pull the heat away or transferring the heat to the external case skin (metal)

Lastly the size of the fan makes a big difference, don't get caught up with these Heatsinks with a fan they really don't help as the fin area is not large enough to shed the heat.

The last bugaboo is the mating surfaces of the chips to the heat sink. Ideally the thinner the material the better and removing labels is also important as they tend to reduce the heat transfer as well. We sometimes need to use different thicknesses of thermal pad (and type) if the chips are at different elevations (we need good compression as well). Again to be clear thin is in! The thinner the thermal pad is the better as we want to move the heat to the mass so the chips are at their ideal heat level.

We also can encounter needing to transfer the heat from both surfaces (many newer Blade SSD use both sides for holding the flash chips) So we have to bring the heat from the back side to the upper side and using adapters can get in the way as well as close spacing to the logic board.

So there you have it the fine art of SSD cooling!

The heat issue is a real issue. But as mentioned, it depends on a lot of factors. The issue of compatibility also depends. There are many things to consider.

As with OWC improvements over the years, so have other products. That includes the adapters, storage chips & circuitry, and even the Macs themselves. For instance, 2015 MacBook Pros don't have the same sleep issues as previous models. Samsung blades use much more power than most others. Sabrent makes some of the most efficient. Trying to save a couple of dollars on cheaper adapters isn't wise. Just like it's unwise to buy counterfeit power supplies or aftermarket batteries. Save a few bucks now, and pay a lot more later. You rarely get more than what you pay for.

So before jumping in and spending many hundreds, on anything, do your due diligence!

@AnnoniMoose - No! The M.2 Spec has not been altered the signal lines are the same as day one. The issues are the same across all M.2 SSD's and adapters - Then and now.

Refinements in the technology helps that's for sure! That is just what Apple has done with their own SoD development. But they own the AP across all of the elements of the iPhone and now with the M series SoC's they own it too.

Sabrent Vs Samsung is a pontless argument as you missed the point! This is not which M.2 SSD is better, it is what plays within the system without failure. I've taken out both M.2 SSD's out as they failed!

The custom Samsung SSD's made to Apples specs are different! Extra data lines and the SSD's micro-controller uses a different code set (Samsung modified by Apple). OWC as well as Transcend made the effort to fully emulate the interface and micro-controller firmware functions. If the M.2 SSD's offered this same level of compatibility I wouldn't have any issue using them.

I'll agree Apple messed up! They should have stuck with the M.2 standard than doing their own thing. Getting the needed alterations to the interface (added signal lines) at least within the M.2 standard (and the standards group should have listened to the needed alterations). Apple closing things off like they did was a mistake!

I like M.2 SSD's! I used them in my AMD Threadripper system which is now doing my heavy large image processing I do as the 2019 Mac Pro was outside of my budget. Sadly, its never got its chance as COVID has mostly sidelined me.

I posted an image of the heat sink design that is ideal above. I had gotten 20 custom units to setup a few systems for video rendering.

@arizonabay - A 4TB SSD will in fact run hotter!

This gets complicated! The major issue is the density of the flash cells get tighter the hotter the logic runs as you use it. So with two SSD's that use different density of chips of the same logic generation the less dense will run cooler! Likewise an SSD which uses more chips also runs hotter. This follows the same problem HDD's a CPU's faced as there density and performance improved they too got hotter. Dammed and double dammed!

So what to do?? Laptops don't have the space to add proper heatsinks and the benefit of a heatsink only goes so far. We often forget the function of a heatsink is two fold: one to offer a mass to hold the heat and a means to radiate it away. With CPU's/GPU's we can see the full solution a large block of metal to transfer away the heat, a means to move the heat to a set of fins which has a fan blowing across.

Sadly these M.2 copper blocks only offer the mass and no means to move the heat away. Think of it this way you have a cup and you fill it with water it can't hold more than what the cup can hold, so once these get to temp you can't add more heat to them and as there is no fins to allow the fans drafting to reduce the heat buildup more quickly you don't really improve things as its not the short hits that we worry about its the long write events.

Here we are dependent on the drafting of the fan to pull the heat away but we don't have an effective means to move the heat away directly from the flash chips or space enough for the mass and in this case a passive fin design for the air to run through to pull the heat away.

Then the question is, is the heat buildup within the SSD bad? As it turns out writing works better when running hot!

Don't forget we also don't want to cook the rest of the system either! The answer here is just install a good thermal monitoring app which can also push the fans as the temp gets above a level. I use TG Pro which is one of the best ones out there.

The other issue is being dust free! A system which is loaded with dust and debris will run hot as the ability of the fan to cool things will be impacted but the junk! The last issue is the battery, surprisingly an old battery or one that is well worn requires more power to charge or hold a charge (adding more heat)! So a system which has a battery over four/five years needs to be replaced as well as one that is getting about 850 cycles or more.

I might add your workflow is also a factor here! Massive data work like video rendering also wears the drive faster! It also requires more housekeeping to keep it running. This is where Wear Leveling kicks in which then can push the heat as well! As a cell which has data that is more worn is transferred to a cell that is less worn. So consider your use, maybe it would be better to use an external drive instead!

To get more out of your 2TB drive I would recommend you unload some of the stuff you have on it as the more free space it has the less work it has during Wear Leveling which is likely a big issue here if you have less than 1/4 of the drive empty.