Reddit mentions of ZTC 512GB Armor 42mm M.2 NGFF 6G SSD Solid State Drive. Model ZTC-SM201-512G

512gb m.2 2242 SSDs exist; I have one running on my W550s now.

https://www.amazon.com/ZTC-512GB-Armor-Drive-ZTC-SM201-512G/dp/B00Z8BYOWG

> 512GB models have been announced and should be appearing soon

Not quite true, 512GB models are already available:

www.amazon.com/gp/product/B00Z8BYOWG

http://www.amazon.com/Transcend-Information-512GB-MTS400-TS512GMTS400/dp/B016W1PP5K

Yeah. That sounds like Falco.

It's supported, and that SSD should work, though I only have experience with MyDigitalSSD and ZTC.

I've heard of some issues with Transcend with ChromeOS/Linux, and I'm not sure they've been fixed . . .

Drives I've used and can recommend:

https://www.amazon.com/dp/B00NY4VIPA/

https://www.amazon.com/gp/product/B00EZ2E8NO/

https://www.amazon.com/dp/B00Z8BYOWG/

I have a y410p (basically a 14" y510p) so I can help you out. Just like my laptop, yours can support a minimum of 3 main storage devices; a single 42mm M.2 SSD and 2x 2.5" HDD/SSD drives.

• First of all get yourself a 2242 M.2 format SATA SSD. They look like this and the maximum storage you will get in this form factor is 512GB or about 1/2 a TB. Here's the card I purchased back in 2015. It's relatively expensive nowadays but that much storage in that form factor isn't too common. Use this as your boot drive.
  
• As for the two 2.5" drives, I would recommend a couple of 1TB SSDs. You can get some quality ones like these for around $100-120 this time of year. Just keep a look out for them. One of these SSDs will replace your currently dying mechanical HDD inside the laptop. The second SSD will take the place of your optical drive (DVD drive) and thus will need a caddy.
  
• Here's an example of the caddy you'll need. I picked this one out specifically because it includes a bezel which perfectly fits the exterior of the y510p. I picked up a similar one for my y410p years ago and have had no issues with it. That said once you get it you will need to remove the mounting bracket from your current DVD drive and put it on the caddy. The mounting bracket is that thin piece of black plastic which sort of follows the edge of the DVD drive casing.
  
• As for the second ultrabay graphics card, don't bother. The only way to get a 750/755m ultrabay card for your y510p nowadays is through the secondhand market; and the prices you will pay are way too much for what you're getting. I'll put it to your this way, you could spend a few hundred dollars on a 750/755m ultrabay card + the 170W power adapter you probably don't have; or you could sell your laptop for a couple hundred, add the cost of that ultrabay card and 170W adapter to what you sold and get much more powerful Acer Nitro 5 laptop for $550-600.
  
  Again don't bother with the ultrabay graphics card. Today even 755m SLI overclocked is a joke in terms of performance. At best you'll just beat out a MX150 (basically a GT 1030), but you won't touch a GTX 1050. Take it from someone who had the best scoring 755m SLI setup until a couple of months ago. Your ultrabay is much better used on a second SSD caddy.
  
  If you have any more questions be sure to post them.
  
  ​

I just ordered this ZTC Armor 44mm from Amazon because another user said that it worked on a Broadwell series Thinkpad. Its difficult (impossible) to find a review but the specs look decent and its a good price. I was confused that 42mm is [not] the same as 2242 and that limited my options.

Here is the 500-ish GB SSDs I found so far:

| Item | \$ | Keying | Interface | Command | Compat? | 4K R/W | What's tested | Notes |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------:|--------|-----------------|----------|---------|---------------|----------------|----------------------------------------------|
| Transcend 512GB SATA III 6GB/S MTS430S 42 mm M.2 SSD 430S Solid State Drive TS512GMTS430S | 80.99 | B+M | | SATA III | No | "80,000 IOPS" | (product page) | |
| Transcend 512GB SATA III 6GB/S MTS400S 42 mm M.2 SSD 400S Solid State Drive TS512GMTS400S | 234.99 | B+M | | SATA III | No | | | |
| Sabrent 512GB Rocket NVMe PCIe M.2 2242 DRAM-Less Low Power Internal High Performance SSD (SB-1342-512) | 69.99 | M | PCIe Gen3 x 4 | NVMe | No | 42 | RND4K Q1T1 | On sale |
| Lexar NM520 M.2 2242 512GB NVMe Solid-State Drive (LNM520-512RBNA) | 143.10 | B+M | PCIe Gen3 x 2 | NVMe | Yes | 39.39 | 4KiB Q1T1 | Weird reviews |
| MyDigitalSSD Super Boot 2 (SB2) 42mm (2242) SATA III (6G) M.2 NGFF SSD Solid State Drive (512GB (480GB)) | 89.99 | B+M | | SATA III | No | 30.64 | 4K | |
| Docooler Solid State Drive M.2 2242 Gen32 PCIe NAND Flash 128GB/256GB/512GB SSD NVMe PCIe Flash Netac | 125.99 | B+M | PCIe Gen3 x 4?? | NVMe | Yes | | | no reviews; 2 weeks ship time? |
| KingSpec 2242 NGFF 512GB M.2 SSD SATA III 6Gb/s Internal Solid State Drive for Ultrabook (512GB) | 69.99 | B+M | | SATA III | No | 20.74 | 4KiB Q1T1 | "very low random 4k read/write speeds"; hot? |
| KingSpec 512GB SSD 2242 M.2 NVMe PCIe Gen3x2 3D NAND Internal Solid State Drive for Thinkpad T580 T570 T480S L570 L480,Dell E7450 | 126.98 | B+M | PCIe Gen3 x 2 | NVMe 1.3 | Yes | | | |
| SSD SATA M.2 2242 500GB Dogfish Ngff Internal Solid State Drive High Performance Hard Drive for Desktop Laptop SATA III 6Gb/s … (500GB, M.2-2242) | 71.00 | B+M | | SATA III | No | | | |
| ZTC 512GB Armor 42mm M.2 NGFF 6G SSD Solid State Drive. Model ZTC-SM201-512G | 58.99 | B+M | | SATA III | No | | | |
| Dogfish SSD M.2 2242 500GB Internal Solid State Drive Laptop Hard Drive M2 SSD (500GB) | 75.00 | B+M | | SATA | | | | |
| Dogfish M.2 2242 500GB Internal Solid State Drive Laptop Hard Drive M2 500g (500GB) | 99.00 | B+M | | SATA III | No | | | |

Probably I will try the KingSpec one...

Ok, so i've been doing some digging around,

Based on these pictures: http://thehikaku.net/pc/lenovo/16ThinkPad-X260-2.html

The X260 has the same M.2 slot as the X250.

This guy put an M.2 ssd on the X250 as a bootable drive with no problems: https://www.youtube.com/watch?v=_AuJJyyDJo0

This is the Biggest M.2 SSD i have been able to find: http://www.amazon.com/dp/B00Z8BYOWG/ref=wl_it_dp_o_pd_S_ttl?_encoding=UTF8&colid=2U7R8LL42Q26Q&coliid=I3FG3LKEZW6ISV&psc=1

and lastly, the different types of M.2 slots: https://www.ramcity.com.au/blog/m.2-ngff-ssd-compatibility-list/189