IBM System x range
IBM System x3105
IBM System x3200, x3200 M2, x3250, x3250 M2
IBM System x3350
IBM System x3400, x3450, x3455
IBM System x3500
IBM System x3550, x3550 M2
IBM System x3650, x3650T, x3655, x3650 M2
IBM System x3755
IBM System x3800, x3850, x3850M2
IBM System x3950, x3950 M2
Numbering scheme
2nd digit increments to show capability
3rd digit is a 0 for tower models, and 5 for rack-mount
4th digit is a 0 for Intel processors, and 5 for AMD Opteron
Models with a T at the end are meant for Telco purposes