Reviews - Samsung SSD 840 Series (250GB)

[HEXUS]

£40 cheaper than the 840 Pro, but at what performance cost?

Read more.

[Willzzz]

Looks good to me. While it's clearly a long way behind other drives in some measures, for the typical user it's more than fast enough and well priced.

[Brewster0101]

SATA needs a big update do that they can increase the speeds more of SSD drives. SATA3 does seem to be holding them back.

[Willzzz]

Nah not really, consistency is the most important thing for the typical end user.

If you are really hitting the limits of SATA3 then you should be quite happy, what you notice is when performance dips temporarily.

[CAT-THE-FIFTH]

The 830 will be the main competition for the 840 non-PRO I suspect.

[Willzzz]

While stocks of the 830 hold out.

[Willzzz]

Oh and bundled with a copy of AC3 on Scan.

[watercooled]

Adding a wrinkle into the mix, the number of spare memory cells diminishes as the drive is filled up with data. SSD controllers have no choice but to use the limited spare capacity for wear-levelling for further P/E cycles, which can become problematic when there's, say, only 20GB left. Why? Because the controller needs to keep scrubbing this spare 20GB when data is written and then erased; the rest of the drive's cells are already full and cannot be used for necessary wear-levelling.

You're describing dynamic wear levelling there, modern SSDs use static wear levelling. Free space makes things easier on the controller, but the drive won't essentially wear out a small section of the drive where free space exists - static wear levelling will move static data around (where the name comes from) to free up less-worn blocks. Of course, this adds to write amplification.

Oh and, the next one to use the TLC pun...

[watercooled]

For write durability, there are arguments weighted strongly one way or the other, with either side often dismissing the other as nonsense. The reality is likely somewhere in between;

1000 P/E cycles is heading towards worryingly low, even if someone doesn't knowingly write much to the drive, Windows isn't designed to be read-only and some programs write a surprising amount while appearing to do nothing. For example, I did some of my own testing and besides the obvious temp/cache files, Firefox was writing on the order of a few GB per day to the profile folder for the likes of session/profile backup. Similar story for Chrome. Then of course, there's the aforementioned temp/cache files which, if you're a heavy surfer and watch some videos, can easily rack up the writes. A ~20m Youtube video I just buffered at 1080p is ~800MB. On top of that, there's background tasks like AV updates, Windows updates and such which add up.

On the flip side, actual tests I've seen indicate NAND usually lasts far longer than specified.
http://dangerousprototypes.com/2010/...royer-wrap-up/
http://www.xtremesystems.org/forums/...e-25nm-Vs-34nm

[Willzzz]

Presumably you can set your cache folder on a different drive if this is a real worry?

[watercooled]

Yeah, I have junction points set up myself as I already have another storage drive, but it's not as easy as that in laptops for instance. I'm not suggesting it's a major concern ATM, and hopefully software developers will improve it, but it's something to consider when looking at the writes/day estimates for instance.

[Evans1234]

nice

[Jace007]

Looks very tempting, but i have my eyes on the Pro, coz it'll run Crysis

[joshy989]

Leaning towards the Pro version..hope the extra cash pays off.

[Konstantin1]

Looks very tempting, but i have my eyes on the Pro, coz it'll run Crysis

Hahaha, Pro version for me too, but because of the MLC NAND.

[stilkun]

Sweet, leaning for Pro version as well.