I am having trouble sorting out if Lenovo adapters 42W7888 and 42W8019 step-down the 2.5" hard drive bay 5.0-volts to 3.3-volts for the 1.8" SSD.

Anyone have one and can opine?

Both adapters (42W7888 and 42W8019) you noted contain circuit boards which do purely pin-mapping -- there are no components on them, no voltage conversion/regulation. SATA power connectors can provide 3.3v, 5v, and 12v, so all the adapter needs to do is "map" the proper pins from the SATA connector to the MicroSATA connector given that the SATA power connector has a 3.3v output. See the section titled "Power connectors" in the article below:
http://en.wikipedia.org/wiki/Serial_ATA

Thanks EOMtp.

I read the Wikipedia article. If I read it and your post correctly, no step-down in power circuitry is necessary since SATA itself provides a 3.3-volt lead. The adapter takes the 3.3-volt lead from the SATA feed and maps it to the correct pins for the 1.8" drive.

In short, the adapter will work for my needs.

Sorry to interrupt, as I don't really have anything to add to this thread, but I was just wondering... why would you want to do something like that?

You have that really sweet T520 computer, and of all the things to impose limits on yourself with, I can not understand why a 1.8" SSD. T410s and T420s owners are forced into using these drives, but it seems that you are using it by choice? Why not sell the 1.8" on ebay or to a T420s user here on the board, and then get something good for your machine, such as a Corsair Force GT or a Patriot Pyro?

Lazy, I guess.

I already own two of the 1.8" drives (they are in Dell Adamos that I am retiring).

If you have a choice the 42W7888 storage converter fits the primary drive bay perfectly. The 42W8019 storage converter causes the primary drive bay cover to not fit perfectly flush. The latter though allows the connector to be removed and used in the 2nd hard drive adapter with 1.8" drives so I recommend having at least one of each on hand.

Your mileage may vary.

Brad

I bought these: http://www.ebay.com/itm/170714035944?ss ... 1497.l2649

I'm not sure which it is.

The other reasons I am looking to install the Samsung drives from my Adamo is that I have been pleased with the performance from a subjective user perspective (I haven't run speed tests on them so I don't know objectively how fast they are) and the 256GB size has been fine for me.

I assume there is not much of a market for them as they are bare chips on a board design. There is no case so appeal is likely a bit limited.