Samsung 256GB SSD is World's Fastest

i4u submitted one of many holiday weekend slow news day stories which starts "Samsung Electronics announced today the world's fastest, 2.5", 256GB multi-level cell (MLC) based solid state drive (SSD) using a SATA II interface. Performance data of the new Samsung 256GB SSD features a sequential read speed of 200 megabytes per second (MB/s) and sequential write speed of 160MB/s. The Samsung MLC-based 2.5-inch 256GB SSD is about 2.4 times faster than a typical HDD. Furthermore, the new 256 GB SSD is only 9.5 millimeters (mm) thick, and measures 100.3x69.85 mm. Samsung is expected to begin mass producing the 2.5-inch, 256GB SSD by year end, with customer samples available in September. A 256GB capacity is getting large enough to replace hard-drives for good — now just the prices just need to come down further for large capacity SSDs."

Comments

MLC, not SLC.

[Anonymous Coward]

But it's a Multi-Level Cell based Flash drive, not a Single-Level Cell based Flash drive. The cells hold 4 states, not 2.

High capacity, yes, and apparently high speed as well. Excellent... but also lower reliability. SLC Flash is extremely durable these days, but MLC Flash is not, last I checked, even one tenth as long-lasting.

How much lower? Well... ...frankly, we don't really know yet. We won't really know, as such, until they start to die - which could well be 5-10 years, and if so, that's really not bad - and you might not see the same type of can't-write-blocks failure, but rather a more conventional can't-read-blocks failure. Which would be about as bad as a hard disk crash (and we might have to develop whole new data recovery techniques).

Maybe it might last years longer than a hard drive owing to fewer moving parts. Perhaps it will slowly die, but good write levelling will largely mitigate the issue and overall it'll come out better, or about the same. Or perhaps we're looking at a flaky brick with lower reliability than a Quantum Fireball.

Early adopters, start your engines, because someone's gotta find out.

For enterprise use, it might be wiser to stick to more conservative SLC flash. Past that, all bets are off.

But we're seeing the beginning, here. Hard drives are, slowly, on the way out. It'll be a long phase-out where they are much more cost-effective for a long time... but it is coming. And I, for one, welcome our new nanosecond-seek-time overlords.

Re:Random write ops?

[TheRaven64]

Unless flash has changed a lot since I last looked at it, this isn't quite true. To write a 2KB page, you first need to erase a 128KB block, but you can then write into the remaining 126KB without needing an erase first. If you're using something like LFS or ZFS on your disk, this translates to very fast writes. If you're using a filesystem that doesn't have copy-on-write semantics, then this will still be quite slow because you will rarely encounter this kind of access pattern (you will be more likely to read 128KB, modify 2KB in a buffer and then re-write 128KB, which, as you explained, is very slow since it requires a 128KB read followed by a 128KB write just to write 2KB - the same reason that RAID-5 is slow for writes).