Hi Jose, The B5 series has 48Gbps stack bandwidth and dedicated stacking ports. On the X440-G2 series, stacking is performed over the 10Gig SFP + ports. The frame flow rate of the X440-G2-24p-10GE4 is higher than that of the B5 series. Optionally, you can use the X450-G2-24p-GE4 or X450-G2-24p-10GE4. These switches have special stack connections (like the B5 series) and modular power supplies and fans. But these switches are much more expensive than the X440-G2. More technical data can be found in the release notes.
Regards
Ole