Jeff Kilgroe |
March 7th, 2007 10:26 AM |
Peter, I did mention the adapters in my post, specifically the one from Duel Systems. I only know of one other one that may be coming to market. Realistically, there is very little market for such a product, most PC card devices such as audio, network, peripheral interfaces / USB2, Firewire, SCSI, eSATA, etc.. are all available as ExpressCard with many more to come. Outside of niche products like P2, there is little reason to even produce such an adapter and Duel Systems has said that they're using the beta program to guage interest in the product as it may not even be economical or profitable to produce.
Jon, that's fine the assumption was made about using the Duel adapter. I didn't gather that from reading the initial posts.
Paul, the P2 cards will in fact be the limiting factor for the time being -- as I posted in my last reply. Currently, P2 cards are operating about 62MB/s at the top end, Panasonic claims they will have them up to 80MB/s in the near future. PCMCIA 32 bit CardBus interfaces support up to 129MB/s -- If you want to get real technical, CardBus actually can do 1066Mbps (133.25MB/s) in a unidirectional stream. So P2 cards at this point in time are only utilizing about half of the bandwidth available to them over this interface.
ExpressCard interface is several times faster than PCMCIA. In fact, it's capable of 2.5Gbps (312MB/s) on the base end and can scale beyond that with the same principal of PCI-Express "lanes". Currently I'm unaware of any 4-lane, let alone 16-lane ExpressCard interfaces, but they are coming. There are currently two form factors of ExpressCard slots/devices. EC34 and EC54. Both use the same 26-pin interface, but the number specifies in mm how wide the slot is. The 54mm slot is wider and can support larger cards so device makers can pack more stuff in there. However, it's not really catching on. Seems most computer makers are opting for the space-saving EC34 form factor.
Anyway, with an adapter sucth as the Duel Systems ExpressCard to PCMCIA unit. You don't gain any speed advantages of EpressCard. You're simply mounting a standard PCMCIA 32bit Cardbus interface onto the ExpressCard bus. It still has the same 1066/1033Mbps top-end bandwidth and P2 cards in turn can only run as fast as their internal FLASH memory and controlling ASICs allow. In the world of FLASH, P2 is rathe quick compared to other SD style memory (on which P2 cards are based) because of the interleaved, multi-channel arrangement. However, as far as other FLASH technologies go these days, SD chips and P2 are rather slow. New techniques for manufacturing CF style media as well as upcoming formats like NAND FLASH are a lot faster. At CES some FLASH makers demonstrated CF media capable of 300MB/s. SanDisk and Transcend introduced FLASH based "hard drives" and other standard form factor storage that will have 30MB to 120MB per second rates and will be available later this year. Current NAND tech operates at about 70 to 100 MB/s, but has much lower latency and doesn't deteriorate over time like typical FLASH does. While current CF/SD style FLASH has a long-life, the 250,000 to 1M writes per cell do not meet stringent guidelines for mission-critical military and aerospace applications. NAND does... You can buy a 2.5" 160GB NAND FLASH hard drive righ now for your notebook that can sustain 70MB/s across the entire data volume. The price is just under US$20,000. A real bargain considering the 30GB version was just under $70K when it was released a couple years ago.
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