MP 6,1 Samsung 970 EVO SSD runs hot on Mac Pro 6,1

[MisterAndrew]

Actually, it's a little simpler than that. The 970 is considered a Fast blade rated 2800-3400 speed (or more with some of the latest) while the Crucial P2 and a few others are considered Slow NVMe blades rated 2000–2400 speed.

Here's the dirty little secret: The Mac Pro 6.1 has only a 2-lane PCIe bus, same as all 2013–2014 AHCI Macs. It cannot utilize all 4 lanes of an NVMe 3 x4 SSD. What this means is that a 970 is no faster than a P2 in one of these. Since the slower ones run cooler and cost less, they are the better buy. Oh, they still have RW speeds about 3x faster than the AHCI blades that they replace.

Something I did not see in this thread is the recommendation to replace the BR2032 battery. When NV RAM batteries get too old, these start showing symptoms that mimic GPU failure. Knowledgeable techs will charge to diagnose, replace the battery and voila, it's fixed. A BR2032 costs less than $7 on Amazon. Because of the heat, no one recommends substituting a CR2032 in these even though they are the same electrically—though you could in a pinch to diagnose sudden display issues.

Not exactly. The sk Hynix and Toshiba/KIOXIA SSDs are fast 4 lane blades. They are just much more efficient than the Samsung blades.

 

[tsialex]

Here's the dirty little secret: The Mac Pro 6.1 has only a 2-lane PCIe bus, same as all 2013–2014 AHCI Macs. It cannot utilize all 4 lanes of an NVMe 3 x4 SSD.

The speed limitation of late-2013 Mac Pro blade is because of the PCIe v2.0, not the lane quantity, and it's a 4-lane PCIe v2.0 connection (Apple calls it PCIe Gen2 2GB/s in the system diagram below):

 

[mikehalloran]

Not exactly. The sk Hynix and Toshiba/KIOXIA SSDs are fast 4 lane blades. They are just much more efficient than the Samsung blades.

That doesn't matter. It's still no faster in a 6.1 than a P2.

The speed limitation of late-2013 Mac Pro blade is because of the PCIe v2.0, not the lane quantity, and it's a 4-lane PCIe v2.0 connection (Apple calls it PCIe Gen2 2GB/s in the system diagram below):

You gentlemen missed the point completely.

 

[tsialex]

You gentlemen missed the point completely.

I know what's your point, but incorrect information propagates.

Btw, there are more reasons to buy high-end blades than just bandwidth with sequential transfers.

 

[MisterAndrew]

That doesn't matter. It's still no faster in a 6.1 than a P2.

I know they are not. I meant that your reasoning that the 2 lane blades are cooler because they are slower is incorrect, especially given the fact they aren't faster in the 6,1 like you pointed out.

 

[marsrover2]

I just installed this SSD 970 into the Mac 6.1 and formatted it then did migration, but not all migrated over plus now I can't erase it to start over. Anybody have a solution. The SSD seems like it's locked. I can erase individual files, but not the entire SSD.

 

[mikehalloran]

I just installed this SSD 970 into the Mac 6.1 and formatted it then did migration, but not all migrated over plus now I can't erase it to start over. Anybody have a solution. The SSD seems like it's locked. I can erase individual files, but not the entire SSD.

What macOS?

 

[mikehalloran]

I know they are not. I meant that your reasoning that the 2 lane blades are cooler because they are slower is incorrect, especially given the fact they aren't faster in the 6,1 like you pointed out.

Again, you misunderstood completely. The blade in question is 4 lane, not 2 lane; the bottleneck is the PCIe Gen 2 bus. You even posted a diagram showing this.

 

[aldergood]

Actually, it's a little simpler than that. The 970 is considered a Fast blade rated 2800-3400 speed (or more with some of the latest) while the Crucial P2 and a few others are considered Slow NVMe blades rated 2000–2400 speed.

Here's the dirty little secret: The Mac Pro 6.1 has only a 2-lane PCIe bus, same as all 2013–2014 AHCI Macs. It cannot utilize all 4 lanes of an NVMe 3 x4 SSD. What this means is that a 970 is no faster than a P2 in one of these. Since the slower ones run cooler and cost less, they are the better buy. Oh, they still have RW speeds about 3x faster than the AHCI blades that they replace.

Something I did not see in this thread is the recommendation to replace the BR2032 battery. When NV RAM batteries get too old, these start showing symptoms that mimic GPU failure. Knowledgeable techs will charge to diagnose, replace the battery and voila, it's fixed. A BR2032 costs less than $7 on Amazon. Because of the heat, no one recommends substituting a CR2032 in these even though they are the same electrically—though you could in a pinch to diagnose sudden display issues.

Hi @mikehalloran ,

Its been a while for this thread but could you describe in more details for the BR2023 sympton when it's too old and especially when it mimic the GPU failure?

 

[mikehalloran]

Hi @mikehalloran ,

Its been a while for this thread but could you describe in more details for the BR2023 sympton when it's too old and especially when it mimic the GPU failure?

With many Macs, diagnosing the GPU was easy. Remove the battery and see if everything works.

Having no battery causes the settings not to be saved but a weak battery can cause all sorts of problems. Same as a car where a weak battery can cause an inexperienced mechanic to misdiagnose the alternator then, after replacement, recommend the battery be replaced.

Never, ever try to diagnose anything without a known good battery. The last Mac Pro 6.1s were made in 2018, sold in 2019 so the newest battery is six years old in that furnace.

The problem is easy to see. Start your Mac. Your screen colors will be all wrong or black. Sometimes, shut down and restart, everything looks good.

Go on Macrumors, read all of the armchair experts regale about GPU problems, many of them quite real, but none of them have seen your Mac. Because of the heat, Apple did have problems with these.

Take it into a shop, commit to the diagnostic. Tech calls and tells you it's done. Pay the diagnostic plus repairs which will include $25 for the battery.

or…

Replace the battery. See if you still have a problem. Unfortunately, the Mac Pro 6.1 is time consuming but not hard if you are handy with tools.
NV RAM Battery Mac Pro 6.1

With many Macs, the common CR2032 battery works great but the MP 6.1 runs hot enough that one should use the heat resistant BR2032, easily found on Amazon.

This problem plagued the 2010–2012 iMacs that shipped with a blistering hot hard drive. Always interesting to see what failed first—the battery or the solder joints in the GPU.