I/O channels on PT24

I have a hard time figuring out how many I/O's you can possibly have on a standard Pro Tools 24 system. I bought an used PT24(1 d24 card, 1 DSP Farm card and 5.1.1 software) last summer. I have until now used 2 888-interfaces(16 I/O channels)with this system, and I want to add 8 more I/O's by using a 888/24 interface. As far as I know, this should not be a problem, since a d24 card handles up to 16 I/O's(two 888-interfaces connected with an optional Y-cable) and a DSP Farm handles 8 I/O's. My question is: Am I correct, or am I completely out of line here? Is Pro Tools 24 able to handle 24 I/O's without occupying all DSP power available? I appreciate any help or good advice I can get from you experienced PT-users out there. Greetings from Norway Hans J

16 i/o per card. pt24 can handle 32 i/o.

'Y' your d24 and add the 3rd 888 to the farm. You'll get your 24 channels of I/O but not much dsp to spare. I think you'll use up a chip of dsp. Get a Mix farm to add to the system.

Thanks for your answers. It really helped. I have to buy that 888/24 now, and maybe a Mix Farm as well...