At 7mm the Silicon Power Slim S55 is perfect for older ultraportables that need a drive upgrade, though they will certainly slip into a 2.5" bay in any system.  The drive uses the Phison PS3110-S10, found in a variety of drives which Al compared last summer.  The controller is paired with a 128MB cache of Nanya DDR3 and TLC NAND, which lowers the price to an impressive $65 for the 240GB model.  It also performs decently, eTeknix saw 556MB/s in ATTO and 530MB/s in CDM; you can check out more tests in their full review here.

"Silicon Power’s Slim series of solid state drives all come with a 7mm thickness, making them perfect for ultrabooks and similar portable computers that require this form factor. Traditional 2.5-inch mechanical drives mostly come with a 9.5mm thickness, ruling them out as an option. The Slim S55 SSD is the little brother in this series, but it doesn’t need to be ashamed of that."

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