A-Tech 24GB KIT (3 x 8GB) for IBM-Lenovo IBM-Lenovo ThinkStation Series D20 (4155-xxx), D20 (4158-xxx) DIMM DDR3 ECC Registered PC3-10600 1333MHz Single Rank Server RAM Memory at Amazon.com
Thinkstation-D20-Motherboard-Replacement - English Community - LENOVO COMMUNITY