Scott Fulton, BetaNews: Every year, solid-state storage advances just a little bit further, often just enough to prompt analysts to ask yet again, when will it be time to declare spinning platters of magnetic data obsolete? If only hard drive technology would just stop rapidly evolving on its own for a little while, perhaps we'd have an answer.

Samsung made some waves at the start of CES week by announcing it's boosting its solid state drive (SSD) capacity to 128 GB, with a new model whose SATA II interface enables it to read data at 100 Mbps. Seek times have never been a problem for memory-based storage, but sustained throughput continues to dog the SSD.

The secret to making SSDs faster -- or, to be more accurate, fast enough to be considered viable technologically as an HDD substitute -- is a NAND flash memory technology called multi-level cell first introduced on the scene last month by Toshiba. It literally goes to the core of what memory is all about, replacing the binary bits we all thought would be a permanent feature of memory with cells that can assume four electrical states -- quaternary digits ("quats?") rather than binary.

But while Samsung boasts of a mean-time-between-failure of one million hours, competitors in the storage space such as Seagate have repeatedly warned us that memory fabricators' standards for determining "failure" are different than those of hard drive manufacturers. What a memory manufacturer might let pass, a Seagate engineer once told me, his company might stamp as an outright defect.

So will these dueling technologies keep evolving on parallel paths rather than perpendicular, and will the scale and capacity of HDDs keep evolving proportionately with those of SSD? We asked our CES analyst, Sharon Fisher.

Sharon Fisher, BetaNews Senior CES Analyst: The question of "when will flash storage replace hard drives" has been asked for years, and this year's CES is no exception. There were several really interesting flash drive announcements, including a 72 GB drive from SanDisk, a 128 GB drive from Samsung, and an enormous 832 GB drive from BitMicro, due to ship late this year. Intel also demonstrated a drive with capacities of 40-120 GB, and Toshiba had one as well.

Flash storage offers several advantages over hard drives. It's lighter - SanDisk said its drive weighed 30% less than a comparable hard drive -- more rugged, takes less power, and has a faster access time.

There are some disadvantages, though: While flash can read faster, rotating hard-disk drives can often write faster. There is also some concern about how many times you can write to flash storage.

But the biggest problem with flash storage is price. Intel, for example, said its flash drive would cost three times as much as a standard drive. Several of the other vendors didn't say how much their products would cost. iSuppli reportedly predicted at CES that pricing will drop from $8.50 per GB now to $.88 per GB in 2011 - but traditional hard drives would drop from $.47 per GB now to $.11 per GB in 2011. In other words, flash storage will still cost eight times as much in 2011.

As flash prices continue to drop, sales are going up; iSuppli reportedly predicted at CES that flash drive sales would rise from 84,000 units in 2007 to 55.8 million units by 2011. However, 30% of these would be for laptops, where the weight difference really matters; enterprise flash storage would only be 2-3% of the market.