Dave wrote: > On 1/6/2010 4:21 PM, Sebastian Kuzminsky wrote: >> There is currently nothing to be gained by using the 5i23 over the 5i20, >> but there are two possible future advantages that may become real some >> time. One is that the 5i23 has a 400 Kgate FPGA (vs the 200 Kgate FPGA >> on the 5i20), the other is that the 5i23's PCI chipset can support DMA. >> >> There are currently no hostmot2 firmwares that don't fit in 200 Kgates, >> and the EMC2 hostmot2 driver does not currently use DMA. But who knows >> that 2010 will bring? > > OK Seb, if it was your money and you were going to buy the board set to > use for the next few years, which one would you buy? :-)
I'd get the 5i20. ;-) > How close is the existing FPGA program to running out of the 200K gate > space?? Hm... Not sure about this one. All the "pwm+encoder" servos and steppers you could possibly want fit in 200K. I think more room becomes useful mostly if you want to hook up other kinds of esoteric equipment like SPI and SSI sensors (like ADCs and resolvers), etc. Or for other firmwares, like SoftDMC, which puts a dedicated processor on the FPGA in addition to all the HostMot2-like motion control stuff. So, probably 200K is plenty for most folks. > Does adding DMA make sense? The 5i2* series of cards do fine without DMA since they sit right on the PCI bus, but the 3x20 would *really* benefit from DMA because it sits behind an on-board PCIE-to-PCI bridge. I'm not sure how much speed improvement the 5i2* boards would get from DMA, they're pretty freaking fast already... -- Sebastian Kuzminsky ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
