Samsung released a patch to fix the performance your 840 EVO SSD might lose over time.
Samsung Fixes 840 EVO SSD Performance Drop With Firmware Patch : Read more
Samsung Fixes 840 EVO SSD Performance Drop With Firmware Patch : Read more
Wouldn't this degrade the drive over time, costing extra write cycles even if the data is mostly just read only? I keep my games on a 500GB 840 EVO. They don't see a whole lot of writes (Magician shows barely one fifth the writes to that drive compared to my 840 Pro OS drive that is half the size) so I figured the drive would last for a long time. This doesn't sound like a fix. More like a workaround.
The article is misleading. Samsung is supplying a utility that updates the firmware and rewrites old sectors. The utility fixes the problem. The firmware prevents it from happening again. Samsung Magician does not provide either part at the moment.