Lenovo Thinkpad X240 Ram Slots

Memory Speed Processor Graphics i3-4010U 24. Some: Single-sided M.2 SSD, via M.2 card slot, exclusive with Smart card reader. ThinkPad X240.indd. Detailed Specifications - ThinkPad X240. About Lenovo + About Lenovo.

Hi guys,

Unlike the ThinkPad X1 Carbon, the somewhat thicker X240 has upgradable internals including a 2.5' drive bay, mSATA bay, RAM slot and a socketed wireless card.

I got a few questions regarding upgrade of my X240. I learnt that X240 has 2 slots for M.2 SSD. One is occupied by a 16GB SSD cache drive (this is what I find in my device manager) and the other is for WIFI card. I wanna replace the 16G SSD with a new SSD as windows drive, keep the HDD and upgrade to 8GB ram as 16GB is not supported.
My questions are:

Lenovo Thinkpad T440s

Lenovo Thinkpad X240 Ram Slots Upgrade

1. Is it any 2242 m.2 SSD with be OK? Which model is crecommended? 128GB or 256GB?
2. Some said the slot is for cache drive only. Is it really OK use it for windows drive?

Lenovo Thinkpad X240 Review

Comparison Criteria Summary multimedia performance memory display details peripherals general information networking storage battery ports others	X Lenovo Thinkpad X240 (20ALA0K-WIG) Ultrabook (Core i5 4th Gen/4 GB/1 TB/Windows 8)	X Lenovo Thinkpad X250 (20CLA0EBIG) Ultrabook (Core i5 5th Gen/4 GB/1 TB/Windows 8)	X Lenovo Thinkpad X260	X
storage 1 TB HDD 1 TB HDD 512 GB SSD processor Intel Core i5 (4th Gen) Processor Intel Core i5 (5th Gen) Processor Intel Core i7 (6th Gen) Processor display 12.5' (31.75 cm) display, 1366 x 768 px 12.5' (31.75 cm) display, 1366 x 768 px 12.5' (31.75 cm) display, 1366 x 768 px ram 4 GB DDR3 RAM 4 GB DDR3 RAM 8 GB DDR4 RAM
multimedia
secondary camrearfacing inbuilt microphone sound technologies Dolby Advanced Audio Dolby Enhanced Audio Dolby Advanced Audio v2 webcam audio solution HD Audio Solution HD Audio Solution HD Audio Solution speakers Stereo Speakers Stereo Speakers
clockspeed 1.6 Ghz 2.2 Ghz 2.5 Ghz graphic processor Intel HD 4400 Intel HD 5500 Intel HD chipset Intel HM87 Express - processor Intel Core i5-4200U (4th Gen) Intel Core i5-5200U (5th Gen) Intel Core i7-6500U (6th Gen)
memory
ram type DDR3 DDR3 DDR4 memory layout 1 x 4 Gigabyte 1 x 4 Gigabyte 1 x 8 Gigabyte memory slots 1 DIMM 1 DIMM expandable memory 8 GB 8 GB capacity 4 GB 4 GB 8 GB
display type LED LED LCD display size 12.5 Inches (31.75 cm) 12.5 Inches (31.75 cm) 12.5 Inches (31.75 cm) display resolution 1366 x 768 Pixels 1366 x 768 Pixels 1366 x 768 Pixels display touchscreen display features HD LED Anti-glare HD display LED Backlit, Anti-Glare Display HD LCD display with IPS technology
peripherals
keyboard ThinkPad Precision Keyboard Full-sized, spill-resistant keyboard Standard Keyboard backlit keyboard - pointing device Touchpad with Multi-touch Gesture Support Touchpad with Track Point Touchpad with Multi-touch Gestures support fingerprint scanner
dimensionswxhxd 305 x 208 x 20.3 mm 305 x 208 x 20.3 mm 305 x 208 x 20.3 mm operating system type 64-bit 64-bit 64-bit weight 1.3 Kg 1.31 Kg 1.3 Kg operating system Windows 8 Windows 8 Professional Windows 10 model X240 (20ALA0K-WIG) X250 (20CLA0EBIG) X260 (20F5A050IG) brand Lenovo Lenovo Lenovo colors Black Black Black
networking
wireless lan 802.11 b/g/n 802.11 b/g/n 802.11 a/b/g/n/ac bluetooth bluetooth version 4.0 4.0 4.1
hdd speedrpm 5400 RPM 5400 RPM hdd capacity 1 TB 1 TB hdd type SATA SATA
battery
battery life 9 Hrs 9 Hrs battery cell 6 Cell Cell 6 Cell Cell 6 Cell battery type Li-Ion Li-Ion Li-Ion
sd card reader vga port usb 30 slots 2 1 2 microphone jack headphone jack usb 20 slots 1 1
others
sales package Laptop, Battery, AC Adapter, User Guide Ultrabook, Battery, AC Adapter, User Guide Ultrabook, Battery, AC Adapter, User Guide warranty 1 Months 3 Years 3 Years
Price ₹ 90,197 ₹ 80,500 ₹ 114,480 Details Full Details » Full Details » Full Details »