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Question Mac folk: Intel 660P shows up as 2x PCIe lanes in my MacBook Pro - supposed to be 4x. Troubleshooting tips appreciated!

reezekeys

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I have a late-2013 15" MacBook Pro and decided to try the "unofficial" SSD upgrade route that maybe a few others here have done: using the Sintech sled adapter card to put a standard M.2 NVMe drive into the MBP's proprietary SSD slot.

I believe I've done everything needed to make this a successful upgrade (eventually, as I'll explain below!):

1- update MacOS on the existing stock SSD to Mojave (10.14.6), which installs the firmware to allow the MBP to boot from a standard NVMe drive.

2- Install the 660P, boot from a USB stick with a bootable Mojave installer, initialize the SSD.

3- Install MacOS on the 660P.

My computer boots from the 660P and works, however the "System Reports" shows the "Link Width" (PCIe lanes) as "2x" where it should be 4x. The interesting (and frustrating) thing is that when I first installed the drive, I initialized it incorrectly with an Apple Partition Map and HFS+ file system. I then restored my system and user data from a Time Machine backup and weirdly enough my MBP booted from the SSD (Intel Macs are supposed to not be bootable from APM drives, only those with GUID partition maps). At that time I ran the Blackmagic Disk Speed test and got 4x speed, around 1400MB/sec read & writes (my computer does PCIe 2.0, not 3.0). After noticing some weird stuff like the Startup Disk setting not sticking, I discovered the mistake I'd made initializing the drive. I reinitialized it with a GUID partition scheme and APFS file system. To be safe I downloaded a fresh Mojave 10.14.6 installer, re-installed the OS and now my PCIe lanes are showing as 2x and read/write speeds have halved!

So far I have done only what's obvious to me to try and troubleshoot why I'm only at 2x: reset the SMC & NVRAM, and cleaned and re-seated the Sintech adapter sled and SSD (I'm fairly confident they are installed correctly).

Could this be a malfunction in the SSD or adapter card? My research has shown that I am running the latest Boot Rom Version for my machine (156.0.0.0.0) and the fact that I can boot the computer from the SSD shows that I must have done that part right. A lot of this stuff is a bit above my pay grade but I'm not afraid to type some terminal commands if anyone knows of tools that might help me get to the bottom of this. What would cause a disk that's known to support 4x lanes show up as 2x? Thanks in advance for any replies!
 
Last edited:

LordVile

Admirable
I have a late-2013 15" MacBook Pro and decided to try the "unofficial" SSD upgrade route that maybe a few others here have done: using the Sintech sled adapter card to put a standard M.2 NVMe drive into the MBP's proprietary SSD slot.

I believe I've done everything needed to make this a successful upgrade (eventually, as I'll explain below!):

1- update MacOS on the existing stock SSD to Mojave (10.14.6), which installs the firmware to allow the MBP to boot from a standard NVMe drive.

2- Install the 660P, boot from a USB stick with a bootable Mojave installer, initialize the SSD.

3- Install MacOS on the 660P.

My computer boots from the 660P and works, however the "System Reports" shows the "Link Width" (PCIe lanes) as "2x" where it should be 4x. The interesting (and frustrating) thing is that when I first installed the drive, I initialized it incorrectly with an Apple Partition Map and HFS+ file system. I then restored my system and user data from a Time Machine backup and weirdly enough my MBP booted from the SSD (Intel Macs are supposed to not be bootable from APM drives, only those with GUID partition maps). At that time I ran the Blackmagic Disk Speed test and got 4x speed, around 1400MB/sec read & writes (my computer does PCIe 2.0, not 3.0). After noticing some weird stuff like the Startup Disk setting not sticking, I discovered the mistake I'd made initializing the drive. I reinitialized it with a GUID partition scheme and APFS file system. To be safe I downloaded a fresh Mojave 10.14.6 installer, re-installed the OS and now my PCIe lanes are showing as 2x and read/write speeds have halved!

So far I have done only what's obvious to me to try and troubleshoot why I'm only at 2x: reset the SMC & NVRAM, and cleaned and re-seated the Sintech adapter sled and SSD (I'm fairly confident they are installed correctly).

Could this be a malfunction in the SSD or adapter card? My research has shown that I am running the latest Boot Rom Version for my machine (156.0.0.0.0) and the fact that I can boot the computer from the SSD shows that I must have done that part right. A lot of this stuff is a bit above my pay grade but I'm not afraid to type some terminal commands if anyone knows of tools that might help me get to the bottom of this. What would cause a disk that's known to support 4x lanes show up as 2x? Thanks in advance for any replies!
Is the slot in the MacBook 4x or only 2x?
 
I thought the 660P was merely an 2x lanes device, regardless of what your mainboard is capable of...

However, I see lots of specs listings showing 4x lanes.....not sure which is correct.

EDIT: (Intel's specs clearly say x4 PCI-e lanes...maybe it was the 'roughly half speed' performance relative to the Samsung 960/970 that made me think it was x2 lanes for so long...)
 
Last edited:

reezekeys

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Thanks for the replies! Yes the 660P is a 4x drive. Everything I've read regarding my particular MacBook Pro says that once the firmware is updated (by updating the original SSD's system to OSX High Sierra or above) the motherboard supports four PCIe lane NVMe drives. This is true even though the original SSD is an AHCI device with two lanes; updating the firmware "unlocks" four lane capability.

I have an ever-shortening window where I can return the drive. I'm hoping Amazon won't give me trouble but I see no other option except to assume it's the drive. I suppose it's possible the adapter "sled" is at fault but that's a very simple piece that just converts the non-standard keying in my MacBook Pro to the standard NVMe's M.2 keying - it has no active components.

I wish there was some kind of utility - even one I run from the Terminal – that might explain why the drive is being seen as 2x. I've looked at the system log for clues, even though 99.9% of what I read is gobbledygook; I'm just looking for any mention of "PCIe" or "Link Width" in the bootup sequence, but see nothing.
 

reezekeys

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Jan 4, 2010
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I thought the 660P was merely an 2x lanes device, regardless of what your mainboard is capable of...

However, I see lots of specs listings showing 4x lanes.....not sure which is correct.

EDIT: (Intel's specs clearly say x4 PCI-e lanes...maybe it was the 'roughly half speed' performance relative to the Samsung 960/970 that made me think it was x2 lanes for so long...)
I resolved my situation, and it turned out to be the Sintech adapter sled. I got lucky because I remembered that 5 months ago I upgraded my daughter's 13" early 2015 MacBook Air with a budget 256GB NVMe drive & the same Sintech sled. I swapped my Intel SSD into her computer and it came up as 4x! I re-installed the 660P into my MacBook Pro using her adapter, and it's now showing up as 4x instead of 2x like before.

This should be a cautionary tale because I assumed these Sintech sleds have no active components on them. I thoroughly inspected mine when I first encountered the issue of my drive showing up as 2x instead of 4x. Nothing stood out as wrong on a visual inspection, but I still cleaned the contacts with IPA and used canned air to blow out any possible debris. I was also careful to make sure the drive was seated all the way into the sled and the sled into my MBP's connector.

Rather than return the defective adapter, I installed it into my daughter's MBA, the reason being her SSD is a 2x device! Nothing has changed with her disk performance.

Here are the speeds I'm seeing now. Again, this is a late-2013 MacBook Pro, Intel 660P 1TB drive, OSX 10.14.6:

 

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