On Mar 28, 2008, at 10:10 AM, Steve Meier wrote: > High speed memory is now staggering the transmission of each data line > to minimize cross talk. High end fpga's can support qdr II memory > devices to clock speeds of over 500 MHz. The qdr ii has two data buses > one for read and one for writing. Each bus supports a transfer on each > edge of the clock. This implies data rates on these buses of over 1 > GHz. > > It isn't the bus rate that will limit performance it is the internal > clock rate. 500 MHz as opposed to over 3 GHZ. >
when you move to serial data buses they have PLL clock multipliers that make the serial stream operate at high frequencies. so the I/O speed can be higher than the fabric speed. hardkrash > However, the fpga has all those built in multipliers.... hundreds of > them. So for certain tasks an fpga will completely blow away a > standard > intel based computer. > > My inclination would be to build a mother board with both a standard > microprocessor and an additional fpga that can be programed by the > microprocessor. A customized coprocessor so to speak. > > Steve Meier > > > > > On Thu, 2008-03-27 at 19:08 -0400, DJ Delorie wrote: >>> My understanding is that with the GHz busses on modern mobos you >>> need >> >> With a soft CPU, the busses can go slower. I wouldn't expect such a >> project to compete with PCs. >> >>> I thought it was basically impossible to get it right without >>> assistance from the CAD tool. >> >> Well, we can change the CAD tool, can't we? ;-) >> >>> Is this actually practically feasible with a "dumb" CAD tool like >>> pcb? >> >> You'd have to limit yourself to something that fits in our skill set, >> sure, but perhaps a less-than-GHz system would be doable. It would >> be >> neat to experiment with other cores and stuff besides the usual x86, >> arm, and mips. Imagine a picoblaze PC running something like DOS, or >> a nios-linux box. >> >>> But it's "dumb" in the sense that it doesn't really contribute to >>> the layout, >> >> It does have trace measuring, though. >> >> >> _______________________________________________ >> geda-user mailing list >> geda-user@moria.seul.org >> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > > > _______________________________________________ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
