Samsung 840 120GB SSD Review

The 120GB Samsung 840 Series SSD features the powerful 8-channel MDX controller and TLC NAND. While this value SSD comes at a very good price, it also features much lower speeds than its larger capacity brethren. We put this value SSD through our suite of steady state tests to see if it can pass muster.



AS SSD is the premier SSD only benchmark. Used widely, it does a good job of keeping the results simple, yet relevant. The benchmark tests with incompressible data, so it doesn't always give a fair shake to drives that rely upon compression for speed.

AS SSD includes a compression benchmark built into the utility. This does an excellent job of addressing the performance with varying levels of compression. It should be taken into consideration that AS SSD measures latency at a 512b file size, when 4k QD1 is actually the industry accepted method.

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The AS SSD benchmark illustrates the performance with incompressible data. The MDX controller does not utilize compression for any of its write speeds, but in this case it sure would help. The 97.6 MB/s in random write speed is among the lowest of modern controllers that we have witnessed.

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AS SSD Write testing shows the 120GB 840 at the bottom of the pack, as per expectations. The high QD random write scaling is particularly weak in this case.

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AS SSD Read measurements reveal that the 120GB 840 can leverage its read speed to post a decent result, beating all non-MDX controlled SSDs.

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AS SSD Copy benchmark illustrates the speed of processing various files in a copy scenario. The 120GB 840 scores the lowest in this test.

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Power Testing is very important, as the lower power appetite for SSDs is a big motivator for users with mobile devices, such as laptops and notebooks, to purchase a new SSD. The promise of longer battery life, while not always guaranteed, is very tempting for many users. We have tested the SSDs at various settings, with high QD (32) to show the maximum power draw for each scenario. More often than not for mundane tasks such as surfing the net the SSD will be very close to idle power.

The idle power draw of the 120GB 840 is excellent at .28 Watts. The other power measurements across the board are comparatively high when taking into consideration that the other SSDs are much larger capacities, with the exception of the V300. The higher capacity SSDs should draw significantly more power yet only draw a similar, or less, amount in many cases.