SanDisk has just unveiled its latest SSD products, the G4 and P4, and debuted a new SSD form factor, mSATA mini, here at Computex.
The G4 is the performance range that comes in a standard 2.5in form factor and is available in capacities of 64GB to 256GB. Read speeds top out at 220MB/sec while write speed is 160MB/sec. Neither of these figures is particularly high but they're perfectly adequate for general use.
Meanwhile the P4 comes in a variety of PATA and SATA form factors including the new mSATA mini, which at just 26.8 x 30.0 x 3.4mm is half the size of the original mSATA and considerably smaller than any existing SATA form factor. The P4 will come in capacities ranging from 8Gb to 128GB.
Now, the interesting thing about both these drives is they don't use the same old controllers, like Barefoot and Indilinx, that most of the other manufacturers are using. Instead it has developed its own controllers and obviously uses its own 32nm flash memory. As such, it implements its own performance and wear-levelling optimisations that it generically calls AFM. In the case of the G4 the main innovation is ExtremeFFS., which gets round the limitation that SSDs can only erase data in large blocks by writing new data to a new block and marking the old data as invalid. It then goes round and tidies up the old data in idle moments.
As for the P4 series, they use a section of fast, non-volatile, SLC memory as a cache, something SanDisk calls nCache, to act as a buffer for oft-accessed data. It doesn't so much help wear-levelling or improve overall read/write speeds but it should help to prevent stuttering and improve overall performance and unlike similar systems on other drives that use DRAM memory it's resistant to data loss from power failure. We were told an 8GB drive would have around a 500MB nCache.
The fly in the ointment, though, is these drives are not going to be available to consumers for the foreseeable future – they're shipping only to OEMs - so we can't actually see how they perform. SanDisk may be releasing them to retail during the coming months but for the time being we'll just have to stick to saving up for one of these instead.
Link: SanDisk website