7mm hard drive bay
Most drives are currently 9.5mm high. Some new Thinkpads come with 7mm drive bays.
There are many discussions around the internet regarding this, here is a short summary:
- Hitatch Travelstar series that begin with model code "Z". This includes Z7K320, Z5K500, and Z5K320
- Momentus Thin Hard Drives | Seagate
- Micron/Crucial C400 series with "AK" in the model number (see below)
- note that Micron is Crucial's parent company. Micron manufacturers the "C" series while Crucial manufactures the "M" series. Reportedly, only the C series is compatible with the x220.
Modifiable 9.5mm SSD
- Micron/Crucial C300 with the spacer mod. See X220 SSD 7mm Mod (Crucial C300)
- Micron/Crucial C400/M4 with spacer mod. (still waiting on confirmation)
- Not all C400 models require a mod. "AK" = 7mm and "AC" = 9mm. Ex) MTFDDAK256MAM-1K1 = 7mm, and MTFDDAC256MAM-1K1 = 9mm. C4 Product Brief
- Intel X-25M with the spacer mod
- Intel 320 series with the spacer mod. Please note that the four screws that hold both the spacer and the top cover cannot be reused to hold just the top cover in place, since they are too long and stick out. I chose to just put the cover back on without any screws. I figured that the cover wouldn't be able to fall off since there's so little space in the drive bay. Additionally, the rubber sides seem to hold the cover in place.
- Kingston/Intel X25-E
- Crucial M4 CT256M4SSD3 mSATA 256GB SATA III MLC
- Intel 310 series
- MyDigialSSD (waiting confirmation, relatively unknown brand)
- Renice X3 (SF1222) mSATA SSD User Review
- OCZ Nocti
- Intel 510 SSD series
- Vertex 2 and 3 SSD series
- Kingston V100 series
Some people have also sanded off the protruding parts of the case which stop you inserting a 9.5mm drive without the caddy.
The moddable drives listed above tend to have a spacer which can be removed with ease and a top which can be replaced using shorter (M2) screws. Drives without the removable spacer can always be removed entirely from their shell and bodged in place.
Bending the motherboard trick
Absolutely do not attempt this, but it is possible to unmount a good portion of the motherboard and slightly bend the side with the SATA port up, while sliding the over sized drive (without) caddy into the slot. The SATA port will need to be bent down to properly mate with the drive. At this point the drive is now firmly in the case and cannot be removed without performing the same trick in reverse, simply damaging the motherboard, or sanding/Dremeling the "teeth" at the entrance of the slot while the drive is still in the machine, which might ultimately be desirable if security is an issue.