Hi everyone, I'm looking at finally upgrading to an SSD but which one? I know M.2 and PCIe offer faster speeds but is there a real world advantage over just standard SATA in audio production? 

Scale your system's SSDs to your needs.

• SATA SSDs sustain ~530MB/Sec
• M.2 Ultra (PCIe x4) SSDs sustain 3200-3500MB/Sec

IMO, It's overkill to use PCIe x4 SSD for a boot drive.
If you're using disk-streaming sample libraries (and you need heavy polyphony), this is where PCIe x4 SSD is a huge benefit.
 

Thanks Jim, I really appreciate your advice.

SSDs and M2s are super quiet and fast over SATA drives. Today's laptops are probably the most noise cancelled systems you can use as towers still need hefty fans for big CPUs. I use M2s for boot drive, sample libraries and main file storage. SATA for DAW projects.

I just got a new Dell Inspiron 15 (5577 "gaming") laptop.  It came with a 250 GB SSD and as it turns out it is an M2 type (Sandisk X400 M2).  Among other things I plan on using the laptop for "on site" recordings (I have two coming up one this month and one in September).  I installed basic Sonar Platinum on the SSD - all I need as I'll transfer the projects to my desktop DAW for processing and have an external 2TB USB 3.0 hard drive for storing projects and easy transfer to the desktop.
 
I considered adding another drive to the new Laptop, as it has space for a hard drive or "full size" SSD, but the cabling is not there since it came configured with the M2 SSD.  I could upgrade the M2 to a larger size but the external drive should suffice for any recording I'll do with it.

Generally there are sockets for extra drives in laptops, in the place where you're supposed to mount them. I've never seen a laptop where you needed to get your own SATA cabling. Are you sure you're not overlooking something?

soens
SSDs and M2s are super quiet and fast over SATA drives. Today's laptops are probably the most noise cancelled systems you can use as towers still need hefty fans for big CPUs. I use M2s for boot drive, sample libraries and main file storage. SATA for DAW projects.

Disagree with laptops being lowest noise.
 
A laptop is a super confined space.
"Mobile" CPUs and GPUs exist because performance-throttling is necessary to keep the units from overheating.
Due to the proprietary structure and confined space, you're essentially "stuck" with stock cooling options.
Most laptops (especially off-the-shelf) don't expose parameters necessary to control fan performance.
 
With a Tower, you've got a faster CPU... but you have the option of using a *large* heat-sink to dissipate that heat... along with large low-RPM fans.  Most motherboards allow detailed control over fan performance.
A tower based machine can be built to operate extremely quiet... with zero compromise in performance.
 
Laptops have their place...
For a high-performance "workstation", I much prefer a tower.
A tower can be built to *exactly* what you want/need.
ie: My main studio DAW has 10 SSDs (two M.2 Ultra), 6850k CPU, GTX-1060 video... and it's quiet enough to have a condenser mic recording in close proximity.
 

My Hp laptop is far noisier than my studio PC. There's no way to throttle the fans any lower than they are. I can only use it at a live venue where there's already a significant background noise level already and you're a good way from mics and the stage and performers.

Jim, when you talk about M2 (PCIe x4) SSD that's what's also called NVME isn't it. M2 SSDs connect just like other drives to the SATA bus not direct to the PCIe buss so don't benefit from any speed increase beyond ordinary SSD on SATA?

Hi Mike,
 
Yes, M.2 Ultra (PCIe x4) SSDs are NVMe.
They use four PCIe lanes... and sustain ~3200-3500MB/Sec.
 
Standard M.2 SSDs have performance identical to 2.5" SATA SSDs.
 
It can get confusing, because there are SSDs on a PCIe card that use four PCIe lanes (ie: Intel 750 series)
These drives are (also) PCIe x4 and NVMe.  
I'm trying to differentiate...